Virgin import of FSF groff v1.19.2

5 files changed, 778 insertions, 532 deletions

diff --git a/contrib/groff/src/preproc/html/Makefile.sub b/contrib/groff/src/preproc/html/Makefile.sub
index 6a9a75707e7e..0763537a94e6 100644
--- a/contrib/groff/src/preproc/html/Makefile.sub
+++ b/contrib/groff/src/preproc/html/Makefile.sub
@@ -2,5 +2,6 @@ PROG=pre-grohtml$(EXEEXT)
 # MAN1=pre-grohtml.n
 MAN1=
 XLIBS=$(LIBGROFF)
+MLIB=$(LIBM)
 OBJS=pre-html.$(OBJEXT) pushback.$(OBJEXT)
 CCSRCS=$(srcdir)/pre-html.cpp $(srcdir)/pushback.cpp
diff --git a/contrib/groff/src/preproc/html/pre-html.cpp b/contrib/groff/src/preproc/html/pre-html.cpp
index 8869136a6ce7..6f8a46aee0fc 100644
--- a/contrib/groff/src/preproc/html/pre-html.cpp
+++ b/contrib/groff/src/preproc/html/pre-html.cpp
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
      Written by Gaius Mulley (gaius@glam.ac.uk).
 
 This file is part of groff.
@@ -16,7 +16,7 @@ for more details.
 
 You should have received a copy of the GNU General Public License along
 with groff; see the file COPYING.  If not, write to the Free Software
-Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
 
 #define PREHTMLC
 
@@ -34,39 +34,124 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
 #include "defs.h"
 #include "searchpath.h"
 #include "paper.h"
+#include "device.h"
 #include "font.h"
 
 #include <errno.h>
 #include <sys/types.h>
 #ifdef HAVE_UNISTD_H
-#include <unistd.h>
+# include <unistd.h>
 #endif
 
 #ifdef _POSIX_VERSION
-#include <sys/wait.h>
-#define PID_T pid_t
+# include <sys/wait.h>
+# define PID_T pid_t
 #else /* not _POSIX_VERSION */
-#define PID_T int
+# define PID_T int
 #endif /* not _POSIX_VERSION */
 
 #include <stdarg.h>
 
 #include "nonposix.h"
 
+/* Establish some definitions to facilitate discrimination between
+   differing runtime environments. */
+
+#undef MAY_FORK_CHILD_PROCESS
+#undef MAY_SPAWN_ASYNCHRONOUS_CHILD
+
+#if defined(__MSDOS__) || defined(_WIN32)
+
+// Most MS-DOS and Win32 environments will be missing the `fork' capability
+// (some like Cygwin have it, but it is best avoided).
+
+# define MAY_FORK_CHILD_PROCESS 0
+
+// On these systems, we use `spawn...', instead of `fork' ... `exec...'.
+# include <process.h>	// for `spawn...'
+# include <fcntl.h>	// for attributes of pipes
+
+# if defined(__CYGWIN__) || defined(_UWIN) || defined(_WIN32)
+
+// These Win32 implementations allow parent and `spawn...'ed child to
+// multitask asynchronously.
+
+#  define MAY_SPAWN_ASYNCHRONOUS_CHILD 1
+
+# else
+
+// Others may adopt MS-DOS behaviour where parent must sleep,
+// from `spawn...' until child terminates.
+
+#  define MAY_SPAWN_ASYNCHRONOUS_CHILD 0
+
+# endif /* not defined __CYGWIN__, _UWIN, or _WIN32 */
+
+# if defined(DEBUGGING) && !defined(DEBUG_FILE_DIR)
+/* When we are building a DEBUGGING version we need to tell pre-grohtml
+   where to put intermediate files (the DEBUGGING version will preserve
+   these on exit).
+
+   On a UNIX host, we might simply use `/tmp', but MS-DOS and Win32 will
+   probably not have this on all disk drives, so default to using
+   `c:/temp' instead.  (Note that user may choose to override this by
+   supplying a definition such as
+
+     -DDEBUG_FILE_DIR=d:/path/to/debug/files
+
+   in the CPPFLAGS to `make'.) */
+
+#  define DEBUG_FILE_DIR c:/temp
+# endif
+
+#else /* not __MSDOS__ or _WIN32 */
+
+// For non-Microsoft environments assume UNIX conventions,
+// so `fork' is required and child processes are asynchronous.
+# define MAY_FORK_CHILD_PROCESS 1
+# define MAY_SPAWN_ASYNCHRONOUS_CHILD 1
+
+# if defined(DEBUGGING) && !defined(DEBUG_FILE_DIR)
+/* For a DEBUGGING version, on the UNIX host, we can also usually rely
+   on being able to use `/tmp' for temporary file storage.  (Note that,
+   as in the __MSDOS__ or _WIN32 case above, the user may override this
+   by defining
+
+     -DDEBUG_FILE_DIR=/path/to/debug/files
+
+   in the CPPFLAGS.) */
+
+#  define DEBUG_FILE_DIR /tmp
+# endif
+
+#endif /* not __MSDOS__ or _WIN32 */
+
+#ifdef DEBUGGING
+// For a DEBUGGING version, we need some additional macros,
+// to direct the captured debug mode output to appropriately named files
+// in the specified DEBUG_FILE_DIR.
+
+# define DEBUG_TEXT(text) #text
+# define DEBUG_NAME(text) DEBUG_TEXT(text)
+# define DEBUG_FILE(name) DEBUG_NAME(DEBUG_FILE_DIR) "/" name
+#endif
+
 extern "C" const char *Version_string;
 
 #include "pre-html.h"
 #include "pushback.h"
 #include "html-strings.h"
 
-#define DEFAULT_LINE_LENGTH        7   // inches wide
-#define DEFAULT_IMAGE_RES        100   // number of pixels per inch resolution
-#define IMAGE_BOARDER_PIXELS       0
-#define INLINE_LEADER_CHAR      '\\'
+#define DEFAULT_LINE_LENGTH 7	// inches wide
+#define DEFAULT_IMAGE_RES 100	// number of pixels per inch resolution
+#define IMAGE_BOARDER_PIXELS 0
+#define INLINE_LEADER_CHAR '\\'
 
-#define TRANSPARENT  "-background white -transparent white"
-#define MIN_ALPHA_BITS             0
-#define MAX_ALPHA_BITS             4
+// Don't use colour names here!  Otherwise there is a dependency on
+// a file called `rgb.txt' which maps names to colours.
+#define TRANSPARENT "-background rgb:f/f/f -transparent rgb:f/f/f"
+#define MIN_ALPHA_BITS 0
+#define MAX_ALPHA_BITS 4
 
 #define PAGE_TEMPLATE_SHORT "pg"
 #define PAGE_TEMPLATE_LONG "-page-"
@@ -76,78 +161,87 @@ extern "C" const char *Version_string;
 #define REGION_TEMPLATE_LONG "-regions-"
 
 #if 0
-#   define  DEBUGGING
+# define DEBUGGING
 #endif
 
 #if !defined(TRUE)
-#   define TRUE (1==1)
+# define TRUE (1==1)
 #endif
 #if !defined(FALSE)
-#   define FALSE (1==0)
+# define FALSE (1==0)
 #endif
 
-typedef enum {CENTERED, LEFT, RIGHT, INLINE} IMAGE_ALIGNMENT;
-
-static int   postscriptRes    =-1;              // postscript resolution, dots per inch
-static int   stdoutfd         = 1;              // output file descriptor - normally 1 but might move
-                                                // -1 means closed
-static int   copyofstdoutfd   =-1;              // a copy of stdout, so we can restore stdout when
-                                                // writing to post-html
-static char *psFileName       = NULL;           // name of postscript file
-static char *psPageName       = NULL;           // name of file containing postscript current page
-static char *regionFileName   = NULL;           // name of file containing all image regions
-static char *imagePageName    = NULL;           // name of bitmap image containing current page
+typedef enum {
+  CENTERED, LEFT, RIGHT, INLINE
+} IMAGE_ALIGNMENT;
+
+static int postscriptRes = -1;		// postscript resolution,
+					// dots per inch
+static int stdoutfd = 1;		// output file descriptor -
+					// normally 1 but might move
+					// -1 means closed
+static char *psFileName = NULL;		// name of postscript file
+static char *psPageName = NULL;		// name of file containing
+					// postscript current page
+static char *regionFileName = NULL;	// name of file containing all
+					// image regions
+static char *imagePageName = NULL;	// name of bitmap image containing
+					// current page
 static const char *image_device = "pnmraw";
-static int   image_res        = DEFAULT_IMAGE_RES;
-static int   vertical_offset  = 0;
-static char *image_template   = NULL;           // image template filename
-static char *macroset_template= NULL;           // image template passed to troff by -D
-static int   troff_arg        = 0;              // troff arg index
-static char *image_dir        = NULL;           // user specified image directory
-static int   textAlphaBits    = MAX_ALPHA_BITS;
-static int   graphicAlphaBits = MAX_ALPHA_BITS;
-static char *antiAlias        = NULL;           // antialias arguments we pass to gs.
-static int   show_progress    = FALSE;          // should we display page numbers as they are processed?
-static int   currentPageNo    = -1;             // current image page number
+static int image_res = DEFAULT_IMAGE_RES;
+static int vertical_offset = 0;
+static char *image_template = NULL;	// image template filename
+static char *macroset_template= NULL;	// image template passed to troff
+					// by -D
+static int troff_arg = 0;		// troff arg index
+static char *image_dir = NULL;		// user specified image directory
+static int textAlphaBits = MAX_ALPHA_BITS;
+static int graphicAlphaBits = MAX_ALPHA_BITS;
+static char *antiAlias = NULL;		// antialias arguments we pass to gs
+static int show_progress = FALSE;	// should we display page numbers as
+					// they are processed?
+static int currentPageNo = -1;		// current image page number
 #if defined(DEBUGGING)
-static int   debug          = FALSE;
-static char *troffFileName  = NULL;             // output of pre-html output which is sent to troff -Tps
-static char *htmlFileName   = NULL;             // output of pre-html output which is sent to troff -Thtml
+static int debug = FALSE;
+static char *troffFileName = NULL;	// output of pre-html output which
+					// is sent to troff -Tps
+static char *htmlFileName = NULL;	// output of pre-html output which
+					// is sent to troff -Thtml
 #endif
 
-static char *linebuf = NULL;                    // for scanning devps/DESC
+static char *linebuf = NULL;		// for scanning devps/DESC
 static int linebufsize = 0;
+static const char *image_gen = NULL;    // the `gs' program
 
 const char *const FONT_ENV_VAR = "GROFF_FONT_PATH";
 static search_path font_path(FONT_ENV_VAR, FONTPATH, 0, 0);
 
 
 /*
- *  Images are generated via postscript, gs and the pnm utilities.
+ *  Images are generated via postscript, gs, and the pnm utilities.
  */
+#define IMAGE_DEVICE "-Tps"
 
-#define IMAGE_DEVICE    "-Tps"
 
-/*
- *  prototypes
- */
 static int do_file(const char *filename);
 
+
 /*
- *  sys_fatal - writes a fatal error message.
- *  Taken from src/roff/groff/pipeline.c.
+ *  sys_fatal - Write a fatal error message.
+ *              Taken from src/roff/groff/pipeline.c.
  */
 
-void sys_fatal (const char *s)
+void sys_fatal(const char *s)
 {
   fatal("%1: %2", s, strerror(errno));
 }
 
 /*
- *  get_line - copies a line (w/o newline) from a file to the global line buffer
+ *  get_line - Copy a line (w/o newline) from a file to the
+ *             global line buffer.
  */
 
-int get_line (FILE *f)
+int get_line(FILE *f)
 {
   if (f == 0)
     return 0;
@@ -188,10 +282,10 @@ int get_line (FILE *f)
 }
 
 /*
- *  get_resolution - returns the postscript resolution from devps/DESC
+ *  get_resolution - Return the postscript resolution from devps/DESC.
  */
 
-static unsigned int get_resolution (void)
+static unsigned int get_resolution(void)
 {
   char *pathp;
   FILE *f;
@@ -212,7 +306,7 @@ static unsigned int get_resolution (void)
 }
 
 /*
- *  html_system - a wrapper for system()
+ *  html_system - A wrapper for system().
  */
 
 void html_system(const char *s, int redirect_stdout)
@@ -242,29 +336,28 @@ void html_system(const char *s, int redirect_stdout)
 }
 
 /*
- *  make_message - taken from man printf(3), creates a string via malloc
- *                 and places the result of the va args into string.
- *                 Finally the new string is returned.
+ *  make_message - Create a string via malloc and place the result of the
+ *                 va args into string.  Finally the new string is returned.
+ *                 Taken from man page of printf(3).
  */
 
-char *
-make_message (const char *fmt, ...)
+char *make_message(const char *fmt, ...)
 {
   /* Guess we need no more than 100 bytes. */
   int n, size = 100;
   char *p;
   char *np;
   va_list ap;
-  if ((p = (char *)malloc (size)) == NULL)
+  if ((p = (char *)malloc(size)) == NULL)
     return NULL;
   while (1) {
     /* Try to print in the allocated space. */
     va_start(ap, fmt);
-    n = vsnprintf (p, size, fmt, ap);
+    n = vsnprintf(p, size, fmt, ap);
     va_end(ap);
     /* If that worked, return the string. */
-    if (n > -1 && n < size) {
-      if (size > n+1) {
+    if (n > -1 && n < size - 1) { /* glibc 2.1 and pre-ANSI C 99 */
+      if (size > n + 1) {
 	np = strsave(p);
 	free(p);
 	return np;
@@ -272,15 +365,13 @@ make_message (const char *fmt, ...)
       return p;
     }
     /* Else try again with more space. */
-    if (n > -1)    /* glibc 2.1 */
-      size = n+1; /* precisely what is needed */
-    else           /* glibc 2.0 */
-      size *= 2;  /* twice the old size */
-    if ((np = (char *)realloc (p, size)) == NULL) {
-      free(p);  /* realloc failed, free old, p. */
+    else		/* glibc 2.0 */
+      size *= 2;	/* twice the old size */
+    if ((np = (char *)realloc(p, size)) == NULL) {
+      free(p);		/* realloc failed, free old, p. */
       return NULL;
     }
-    p = np;  /* use realloc'ed, p */
+    p = np;		/* use realloc'ed, p */
   }
 }
 
@@ -290,15 +381,15 @@ make_message (const char *fmt, ...)
 
 struct char_block {
   enum { SIZE = 256 };
-  char          buffer[SIZE];
-  int           used;
-  char_block   *next;
+  char buffer[SIZE];
+  int used;
+  char_block *next;
 
   char_block();
 };
 
 /*
- *  char_block - constructor, sets the, used, and, next, fields to zero.
+ *  char_block - Constructor.  Set the, used, and, next, fields to zero.
  */
 
 char_block::char_block()
@@ -312,22 +403,22 @@ class char_buffer {
 public:
   char_buffer();
   ~char_buffer();
-  int  read_file(FILE *fp);
-  int  do_html(int argc, char *argv[]);
-  int  do_image(int argc, char *argv[]);
-  void write_file_html(void);
-  void write_file_troff(void);
-  void write_upto_newline (char_block **t, int *i, int is_html);
-  int  can_see(char_block **t, int *i, const char *string);
-  int  skip_spaces(char_block **t, int *i);
+  int read_file(FILE *fp);
+  int do_html(int argc, char *argv[]);
+  int do_image(int argc, char *argv[]);
+  void emit_troff_output(int device_format_selector);
+  void write_upto_newline(char_block **t, int *i, int is_html);
+  int can_see(char_block **t, int *i, const char *string);
+  int skip_spaces(char_block **t, int *i);
   void skip_until_newline(char_block **t, int *i);
 private:
   char_block *head;
   char_block *tail;
+  int run_output_filter(int device_format_selector, int argc, char *argv[]);
 };
 
 /*
- *  char_buffer - constructor
+ *  char_buffer - Constructor.
  */
 
 char_buffer::char_buffer()
@@ -336,7 +427,7 @@ char_buffer::char_buffer()
 }
 
 /*
- *  char_buffer - deconstructor, throws aways the whole buffer list.
+ *  char_buffer - Destructor.  Throw away the whole buffer list.
  */
 
 char_buffer::~char_buffer()
@@ -349,70 +440,69 @@ char_buffer::~char_buffer()
 }
 
 /*
- *  read_file - read in a complete file, fp, placing the contents inside char_blocks.
+ *  read_file - Read in a complete file, fp, placing the contents inside
+ *              char_blocks.
  */
 
-int char_buffer::read_file (FILE *fp)
+int char_buffer::read_file(FILE *fp)
 {
   int n;
-
-  while (! feof(fp)) {
+  while (!feof(fp)) {
     if (tail == NULL) {
       tail = new char_block;
       head = tail;
-    } else {
+    }
+    else {
       if (tail->used == char_block::SIZE) {
 	tail->next = new char_block;
-	tail       = tail->next;
+	tail = tail->next;
       }
     }
-    // at this point we have a tail which is ready for the next SIZE bytes of the file
-
+    // at this point we have a tail which is ready for the next SIZE
+    // bytes of the file
     n = fread(tail->buffer, sizeof(char), char_block::SIZE-tail->used, fp);
-    if (n <= 0) {
+    if (n <= 0)
       // error
-      return( 0 );
-    } else {
-      tail->used += n*sizeof(char);
-    }
+      return 0;
+    else
+      tail->used += n * sizeof(char);
   }
-  return( 1 );
+  return 1;
 }
 
 /*
- *  writeNbytes - writes n bytes to stdout.
+ *  writeNbytes - Write n bytes to stdout.
  */
 
-static void writeNbytes (const char *s, int l)
+static void writeNbytes(const char *s, int l)
 {
-  int n=0;
+  int n = 0;
   int r;
 
-  while (n<l) {
-    r = write(stdoutfd, s, l-n);
-    if (r<0) {
+  while (n < l) {
+    r = write(stdoutfd, s, l - n);
+    if (r < 0)
       sys_fatal("write");
-    }
     n += r;
     s += r;
   }
 }
 
 /*
- *  writeString - writes a string to stdout.
+ *  writeString - Write a string to stdout.
  */
 
-static void writeString (const char *s)
+static void writeString(const char *s)
 {
   writeNbytes(s, strlen(s));
 }
 
 /*
- *  makeFileName - creates the image filename template
+ *  makeFileName - Create the image filename template
  *                 and the macroset image template.
  */
 
-static void makeFileName (void)
+static void makeFileName(void)
 {
   if ((image_dir != NULL) && (strchr(image_dir, '%') != NULL)) {
     error("cannot use a `%%' within the image directory name");
@@ -424,23 +514,26 @@ static void makeFileName (void)
     exit(1);
   }
 
-  if (image_dir == NULL) {
-    image_dir = "";
-  } else if ((strlen(image_dir)>0) && (image_dir[strlen(image_dir)-1] != '/')) {
+  if (image_dir == NULL)
+    image_dir = (char *)"";
+  else if (strlen(image_dir) > 0
+	   && image_dir[strlen(image_dir) - 1] != '/') {
     image_dir = make_message("%s/", image_dir);
     if (image_dir == NULL)
       sys_fatal("make_message");
   }
-  
+
   if (image_template == NULL)
-    macroset_template = make_message("%sgrohtml-%d", image_dir, (int)getpid());
+    macroset_template = make_message("%sgrohtml-%d", image_dir,
+				     (int)getpid());
   else
     macroset_template = make_message("%s%s", image_dir, image_template);
 
   if (macroset_template == NULL)
     sys_fatal("make_message");
 
-  image_template = (char *)malloc(strlen("-%d")+strlen(macroset_template)+1);
+  image_template =
+    (char *)malloc(strlen("-%d") + strlen(macroset_template) + 1);
   if (image_template == NULL)
     sys_fatal("malloc");
   strcpy(image_template, macroset_template);
@@ -448,10 +541,10 @@ static void makeFileName (void)
 }
 
 /*
- *  setupAntiAlias - sets up the antialias string, used when we call gs.
+ *  setupAntiAlias - Set up the antialias string, used when we call gs.
  */
 
-static void setupAntiAlias (void)
+static void setupAntiAlias(void)
 {
   if (textAlphaBits == 0 && graphicAlphaBits == 0)
     antiAlias = make_message(" ");
@@ -465,23 +558,24 @@ static void setupAntiAlias (void)
 }
 
 /*
- *  checkImageDir - checks to see whether the image directory is available.
+ *  checkImageDir - Check whether the image directory is available.
  */
 
-static void checkImageDir (void)
+static void checkImageDir(void)
 {
-  if ((image_dir != NULL) && (strcmp(image_dir, "") != 0))
-    if (! ((mkdir(image_dir, 0777) == 0) || (errno == EEXIST))) {
+  if (image_dir != NULL && strcmp(image_dir, "") != 0)
+    if (!(mkdir(image_dir, 0777) == 0 || errno == EEXIST)) {
       error("cannot create directory `%1'", image_dir);
       exit(1);
     }
 }
 
 /*
- *  write_end_image - ends the image. It writes out the image extents if we are using -Tps.
+ *  write_end_image - End the image.  Write out the image extents if we
+ *                    are using -Tps.
  */
 
-static void write_end_image (int is_html)
+static void write_end_image(int is_html)
 {
   /*
    *  if we are producing html then these
@@ -499,18 +593,17 @@ static void write_end_image (int is_html)
 }
 
 /*
- *  write_start_image - writes the troff which will:
+ *  write_start_image - Write troff code which will:
  *
  *                      (i)  disable html output for the following image
  *                      (ii) reset the max/min x/y registers during postscript
  *                           rendering.
  */
 
-static void write_start_image (IMAGE_ALIGNMENT pos, int is_html)
+static void write_start_image(IMAGE_ALIGNMENT pos, int is_html)
 {
   writeString("\\O[5");
   switch (pos) {
-
   case INLINE:
     writeString("i");
     break;
@@ -525,7 +618,8 @@ static void write_start_image (IMAGE_ALIGNMENT pos, int is_html)
     writeString("c");
     break;
   }
-  writeString(image_template); writeString(".png]");
+  writeString(image_template);
+  writeString(".png]");
   if (is_html)
     writeString("\\O[0]\\O[3]");
   else
@@ -534,24 +628,25 @@ static void write_start_image (IMAGE_ALIGNMENT pos, int is_html)
 }
 
 /*
- *  write_upto_newline - writes the contents of the buffer until a newline is seen.
- *                       It checks for HTML_IMAGE_INLINE_BEGIN and HTML_IMAGE_INLINE_END
- *                       and if they are present it processes them.
+ *  write_upto_newline - Write the contents of the buffer until a newline
+ *                       is seen.  Check for HTML_IMAGE_INLINE_BEGIN and
+ *                       HTML_IMAGE_INLINE_END; process them if they are
+ *                       present.
  */
 
-void char_buffer::write_upto_newline (char_block **t, int *i, int is_html)
+void char_buffer::write_upto_newline(char_block **t, int *i, int is_html)
 {
-  int j=*i;
+  int j = *i;
 
   if (*t) {
-    while ((j < (*t)->used) && ((*t)->buffer[j] != '\n') &&
-	   ((*t)->buffer[j] != INLINE_LEADER_CHAR)) {
+    while (j < (*t)->used
+	   && (*t)->buffer[j] != '\n'
+	   && (*t)->buffer[j] != INLINE_LEADER_CHAR)
       j++;
-    }
-    if ((j < (*t)->used) && ((*t)->buffer[j] == '\n')) {
+    if (j < (*t)->used
+	&& (*t)->buffer[j] == '\n')
       j++;
-    }
-    writeNbytes((*t)->buffer+(*i), j-(*i));
+    writeNbytes((*t)->buffer + (*i), j - (*i));
     if ((*t)->buffer[j] == INLINE_LEADER_CHAR) {
       if (can_see(t, &j, HTML_IMAGE_INLINE_BEGIN))
 	write_start_image(INLINE, is_html);
@@ -561,208 +656,225 @@ void char_buffer::write_upto_newline (char_block **t, int *i, int is_html)
 	if (j < (*t)->used) {
 	  *i = j;
 	  j++;
-	  writeNbytes((*t)->buffer+(*i), j-(*i));
+	  writeNbytes((*t)->buffer + (*i), j - (*i));
 	}
       }
     }
     if (j == (*t)->used) {
       *i = 0;
-      if ((*t)->buffer[j-1] == '\n') {
-	*t = (*t)->next;
-      } else {
-	*t = (*t)->next;
+      *t = (*t)->next;
+      if (*t && (*t)->buffer[j - 1] != '\n')
 	write_upto_newline(t, i, is_html);
-      }
-    } else {
+    }
+    else
       // newline was seen
       *i = j;
-    }
   }
 }
 
 /*
- *  can_see - returns TRUE if we can see string in t->buffer[i] onwards
+ *  can_see - Return TRUE if we can see string in t->buffer[i] onwards.
  */
 
-int char_buffer::can_see (char_block **t, int *i, const char *string)
+int char_buffer::can_see(char_block **t, int *i, const char *str)
 {
-  int j         = 0;
-  int l         = strlen(string);
-  int k         = *i;
+  int j = 0;
+  int l = strlen(str);
+  int k = *i;
   char_block *s = *t;
 
   while (s) {
-    while ((k<s->used) && (j<l) && (s->buffer[k] == string[j])) {
+    while (k < s->used && j < l && s->buffer[k] == str[j]) {
       j++;
       k++;
     }
     if (j == l) {
       *i = k;
       *t = s;
-      return( TRUE );
-    } else if ((k<s->used) && (s->buffer[k] != string[j])) {
-      return( FALSE );
+      return TRUE;
     }
+    else if (k < s->used && s->buffer[k] != str[j])
+      return( FALSE );
     s = s->next;
     k = 0;
   }
-  return( FALSE );
+  return FALSE;
 }
 
 /*
- *  skip_spaces - returns TRUE if we have not run out of data.
- *                It also consumes spaces.
+ *  skip_spaces - Return TRUE if we have not run out of data.
+ *                Consume spaces also.
  */
 
 int char_buffer::skip_spaces(char_block **t, int *i)
 {
   char_block *s = *t;
-  int k         = *i;
+  int k = *i;
 
   while (s) {
-    while ((k<s->used) && (isspace(s->buffer[k]))) {
+    while (k < s->used && isspace(s->buffer[k]))
       k++;
-    }
     if (k == s->used) {
       k = 0;
       s = s->next;
-    } else {
+    }
+    else {
       *i = k;
-      return( TRUE );
+      return TRUE;
     }
   }
-  return( FALSE );
+  return FALSE;
 }
 
 /*
- *  skip_until_newline - skips all characters until a newline is seen.
+ *  skip_until_newline - Skip all characters until a newline is seen.
  *                       The newline is not consumed.
  */
 
-void char_buffer::skip_until_newline (char_block **t, int *i)
+void char_buffer::skip_until_newline(char_block **t, int *i)
 {
-  int j=*i;
+  int j = *i;
 
   if (*t) {
-    while ((j < (*t)->used) && ((*t)->buffer[j] != '\n')) {
+    while (j < (*t)->used && (*t)->buffer[j] != '\n')
       j++;
-    }
     if (j == (*t)->used) {
       *i = 0;
       *t = (*t)->next;
       skip_until_newline(t, i);
-    } else {
+    }
+    else
       // newline was seen
       *i = j;
-    }
   }
 }
 
+#define DEVICE_FORMAT(filter) (filter == HTML_OUTPUT_FILTER)
+#define HTML_OUTPUT_FILTER     0
+#define IMAGE_OUTPUT_FILTER    1
+#define OUTPUT_STREAM(name)   creat((name), S_IWUSR | S_IRUSR)
+#define PS_OUTPUT_STREAM      OUTPUT_STREAM(psFileName)
+#define REGION_OUTPUT_STREAM  OUTPUT_STREAM(regionFileName)
+
 /*
- *  write_file_troff - writes the buffer to stdout (troff).
+ *  emit_troff_output - Write formatted buffer content to the troff
+ *                      post-processor data pipeline.
  */
 
-void char_buffer::write_file_troff (void)
+void char_buffer::emit_troff_output(int device_format_selector)
 {
-  char_block *t=head;
-  int         i=0;
+  // Handle output for BOTH html and image device formats
+  // if `device_format_selector' is passed as
+  //
+  //   HTML_FORMAT(HTML_OUTPUT_FILTER)
+  //     Buffer data is written to the output stream
+  //     with template image names translated to actual image names.
+  //
+  //   HTML_FORMAT(IMAGE_OUTPUT_FILTER)
+  //     Buffer data is written to the output stream
+  //     with no translation, for image file creation in the post-processor.
+
+  int idx = 0;
+  char_block *element = head;
+
+  while (element != NULL)
+    write_upto_newline(&element, &idx, device_format_selector);
 
-  if (t != NULL) {
-    do {
-      write_upto_newline(&t, &i, FALSE);
-    } while (t != NULL);
-  }
+#if 0
   if (close(stdoutfd) < 0)
-    sys_fatal("close");
+    sys_fatal ("close");
 
   // now we grab fd=1 so that the next pipe cannot use fd=1
   if (stdoutfd == 1) {
-    if (dup(2) != stdoutfd) {
-      sys_fatal("dup failed to use fd=1");
-    }
+    if (dup(2) != stdoutfd)
+      sys_fatal ("dup failed to use fd=1");
   }
+#endif /* 0 */
 }
 
 /*
- *  the image class remembers the position of all images in the postscript file
- *  and assigns names for each image.
+ *  The image class remembers the position of all images in the
+ *  postscript file and assigns names for each image.
  */
 
 struct imageItem {
-  imageItem  *next;
-  int         X1;
-  int         Y1;
-  int         X2;
-  int         Y2;
-  char       *imageName;
-  int         resolution;
-  int         maxx;
-  int         pageNo;
-
-  imageItem (int x1, int y1, int x2, int y2, int page, int res, int max_width, char *name);
-  ~imageItem ();
+  imageItem *next;
+  int X1;
+  int Y1;
+  int X2;
+  int Y2;
+  char *imageName;
+  int resolution;
+  int maxx;
+  int pageNo;
+
+  imageItem(int x1, int y1, int x2, int y2,
+	    int page, int res, int max_width, char *name);
+  ~imageItem();
 };
 
 /*
- *  imageItem - constructor
+ *  imageItem - Constructor.
  */
 
-imageItem::imageItem (int x1, int y1, int x2, int y2, int page, int res, int max_width, char *name)
+imageItem::imageItem(int x1, int y1, int x2, int y2,
+		     int page, int res, int max_width, char *name)
 {
-  X1         = x1;
-  Y1         = y1;
-  X2         = x2;
-  Y2         = y2;
-  pageNo     = page;
+  X1 = x1;
+  Y1 = y1;
+  X2 = x2;
+  Y2 = y2;
+  pageNo = page;
   resolution = res;
-  maxx       = max_width;
-  imageName  = name;
-  next       = NULL;
+  maxx = max_width;
+  imageName = name;
+  next = NULL;
 }
 
 /*
- *  imageItem - deconstructor
+ *  imageItem - Destructor.
  */
 
-imageItem::~imageItem ()
+imageItem::~imageItem()
 {
   if (imageName)
     free(imageName);
 }
 
 /*
- *  imageList - class containing a list of imageItems.
+ *  imageList - A class containing a list of imageItems.
  */
 
 class imageList {
 private:
   imageItem *head;
   imageItem *tail;
-  int        count;
+  int count;
 public:
   imageList();
   ~imageList();
-  void  add(int x1, int y1, int x2, int y2, int page, int res, int maxx, char *name);
-  void  createImages (void);
-  int   createPage (int pageno);
-  void  createImage (imageItem *i);
-  int   getMaxX (int pageno);
+  void add(int x1, int y1, int x2, int y2,
+	   int page, int res, int maxx, char *name);
+  void createImages(void);
+  int createPage(int pageno);
+  void createImage(imageItem *i);
+  int getMaxX(int pageno);
 };
 
 /*
- *  imageList - constructor.
+ *  imageList - Constructor.
  */
 
-imageList::imageList ()
-  : head(0), tail(0), count(0)
+imageList::imageList()
+: head(0), tail(0), count(0)
 {
 }
 
 /*
- *  imageList - deconstructor.
+ *  imageList - Destructor.
  */
 
-imageList::~imageList ()
+imageList::~imageList()
 {
   while (head != NULL) {
     imageItem *i = head;
@@ -772,10 +884,10 @@ imageList::~imageList ()
 }
 
 /*
- *  createPage - creates one image of, page pageno, from the postscript file.
+ *  createPage - Create one image of, page pageno, from the postscript file.
  */
 
-int imageList::createPage (int pageno)
+int imageList::createPage(int pageno)
 {
   char *s;
 
@@ -784,8 +896,9 @@ int imageList::createPage (int pageno)
 
   if (currentPageNo >= 1) {
     /*
-     *  we need to unlink the files which change each time a new page is processed.
-     *  The final unlink is done by xtmpfile when pre-grohtml exits.
+     *  We need to unlink the files which change each time a new page is
+     *  processed.  The final unlink is done by xtmpfile when pre-grohtml
+     *  exits.
      */
     unlink(imagePageName);
     unlink(psPageName);
@@ -813,13 +926,14 @@ int imageList::createPage (int pageno)
   }
 #endif
   html_system(s, 1);
-  
+
   s = make_message("echo showpage | "
-		   "gs%s -q -dBATCH -dSAFER "
+		   "%s%s -q -dBATCH -dSAFER "
 		   "-dDEVICEHEIGHTPOINTS=792 "
 		   "-dDEVICEWIDTHPOINTS=%d -dFIXEDMEDIA=true "
 		   "-sDEVICE=%s -r%d %s "
 		   "-sOutputFile=%s %s -\n",
+		   image_gen,
 		   EXE_EXT,
 		   (getMaxX(pageno) * image_res) / postscriptRes,
 		   image_device,
@@ -842,39 +956,38 @@ int imageList::createPage (int pageno)
 }
 
 /*
- *  min - returns the minimum of two numbers.
+ *  min - Return the minimum of two numbers.
  */
 
-int min (int x, int y)
+int min(int x, int y)
 {
-  if (x < y) {
-    return( x );
-  } else {
-    return( y );
-  }
+  if (x < y)
+    return x;
+  else
+    return y;
 }
 
 /*
- *  max - returns the maximum of two numbers.
+ *  max - Return the maximum of two numbers.
  */
 
-int max (int x, int y)
+int max(int x, int y)
 {
-  if (x > y) {
-    return( x );
-  } else {
-    return( y );
-  }
+  if (x > y)
+    return x;
+  else
+    return y;
 }
 
 /*
- *  getMaxX - returns the largest right hand position for any image on, pageno
+ *  getMaxX - Return the largest right-hand position for any image
+ *            on, pageno.
  */
 
-int imageList::getMaxX (int pageno)
+int imageList::getMaxX(int pageno)
 {
   imageItem *h = head;
-  int x        = postscriptRes * DEFAULT_LINE_LENGTH;
+  int x = postscriptRes * DEFAULT_LINE_LENGTH;
 
   while (h != NULL) {
     if (h->pageNo == pageno)
@@ -885,21 +998,30 @@ int imageList::getMaxX (int pageno)
 }
 
 /*
- *  createImage - generates a minimal png file from the set of page images.
+ *  createImage - Generate a minimal png file from the set of page images.
  */
 
-void imageList::createImage (imageItem *i)
+void imageList::createImage(imageItem *i)
 {
   if (i->X1 != -1) {
     char *s;
-    int  x1 = max(min(i->X1, i->X2)*image_res/postscriptRes-1*IMAGE_BOARDER_PIXELS, 0);
-    int  y1 = max((image_res*vertical_offset/72)+min(i->Y1, i->Y2)*image_res/postscriptRes-IMAGE_BOARDER_PIXELS, 0);
-    int  x2 = max(i->X1, i->X2)*image_res/postscriptRes+1*IMAGE_BOARDER_PIXELS;
-    int  y2 = (image_res*vertical_offset/72)+(max(i->Y1, i->Y2)*image_res/postscriptRes)+1+IMAGE_BOARDER_PIXELS;
+    int x1 = max(min(i->X1, i->X2) * image_res / postscriptRes
+		   - IMAGE_BOARDER_PIXELS,
+		 0);
+    int y1 = max(image_res * vertical_offset / 72
+		   + min(i->Y1, i->Y2) * image_res / postscriptRes
+		   - IMAGE_BOARDER_PIXELS,
+		 0);
+    int x2 = max(i->X1, i->X2) * image_res / postscriptRes
+	     + IMAGE_BOARDER_PIXELS;
+    int y2 = image_res * vertical_offset / 72
+	     + max(i->Y1, i->Y2) * image_res / postscriptRes
+	     + 1 + IMAGE_BOARDER_PIXELS;
     if (createPage(i->pageNo) == 0) {
-      s = make_message("pnmcut%s %d %d %d %d < %s | pnmcrop -quiet | pnmtopng%s %s > %s \n",
+      s = make_message("pnmcut%s %d %d %d %d < %s "
+		       "| pnmcrop -quiet | pnmtopng%s %s > %s\n",
 		       EXE_EXT,
-		       x1, y1, x2-x1+1, y2-y1+1,
+		       x1, y1, x2 - x1 + 1, y2 - y1 + 1,
 		       imagePageName,
 		       EXE_EXT,
 		       TRANSPARENT,
@@ -915,12 +1037,14 @@ void imageList::createImage (imageItem *i)
 #endif
       html_system(s, 0);
       free(s);
-    } else {
+    }
+    else {
       fprintf(stderr, "failed to generate image of page %d\n", i->pageNo);
       fflush(stderr);
     }
 #if defined(DEBUGGING)
-  } else {
+  }
+  else {
     if (debug) {
       fprintf(stderr, "ignoring image as x1 coord is -1\n");
       fflush(stderr);
@@ -930,27 +1054,30 @@ void imageList::createImage (imageItem *i)
 }
 
 /*
- *  add - an image description to the imageList.
+ *  add - Add an image description to the imageList.
  */
 
-void imageList::add (int x1, int y1, int x2, int y2, int page, int res, int maxx, char *name)
+void imageList::add(int x1, int y1, int x2, int y2,
+		    int page, int res, int maxx, char *name)
 {
   imageItem *i = new imageItem(x1, y1, x2, y2, page, res, maxx, name);
 
   if (head == NULL) {
     head = i;
     tail = i;
-  } else {
+  }
+  else {
     tail->next = i;
     tail = i;
   }
 }
 
 /*
- *  createImages - foreach image descriptor on the imageList, create the actual image.
+ *  createImages - For each image descriptor on the imageList,
+ *                 create the actual image.
  */
 
-void imageList::createImages (void)
+void imageList::createImages(void)
 {
   imageItem *h = head;
 
@@ -960,72 +1087,42 @@ void imageList::createImages (void)
   }
 }
 
-static imageList listOfImages;  // list of images defined by the region file.
-
-/*
- *  write_file_html - writes the buffer to stdout (troff).
- *                    It writes out the file replacing template image names with
- *                    actual image names.
- */
-
-void char_buffer::write_file_html (void)
-{
-  char_block *t=head;
-  int         i=0;
-
-  if (t != NULL) {
-    do {
-      write_upto_newline(&t, &i, TRUE);
-    } while (t != NULL);
-  }
-  if (close(stdoutfd) < 0)
-    sys_fatal("close");
-
-  // now we grab fd=1 so that the next pipe cannot use fd=1
-  if (stdoutfd == 1) {
-    if (dup(2) != stdoutfd) {
-      sys_fatal("dup failed to use fd=1");
-    }
-  }
-}
+static imageList listOfImages;	// List of images defined by the region file.
 
 /*
- *  generateImages - parses the region file and generates images
- *                   from the postscript file. The region file
- *                   contains the x1,y1  x2,y2 extents of each
+ *  generateImages - Parse the region file and generate images
+ *                   from the postscript file.  The region file
+ *                   contains the x1,y1--x2,y2 extents of each
  *                   image.
  */
 
-static void generateImages (char *regionFileName)
+static void generateImages(char *region_file_name)
 {
-  pushBackBuffer *f=new pushBackBuffer(regionFileName);
+  pushBackBuffer *f=new pushBackBuffer(region_file_name);
 
   while (f->putPB(f->getPB()) != eof) {
     if (f->isString("grohtml-info:page")) {
-      int page   = f->readInt();
-      int x1     = f->readInt();
-      int y1     = f->readInt();
-      int x2     = f->readInt();
-      int y2     = f->readInt();
-      int maxx   = f->readInt();
+      int page = f->readInt();
+      int x1 = f->readInt();
+      int y1 = f->readInt();
+      int x2 = f->readInt();
+      int y2 = f->readInt();
+      int maxx = f->readInt();
       char *name = f->readString();
-      int res    = postscriptRes;
+      int res = postscriptRes;
       listOfImages.add(x1, y1, x2, y2, page, res, maxx, name);
-      while ((f->putPB(f->getPB()) != '\n') &&
-	     (f->putPB(f->getPB()) != eof)) {
+      while (f->putPB(f->getPB()) != '\n'
+	     && f->putPB(f->getPB()) != eof)
 	(void)f->getPB();
-      }
-      if (f->putPB(f->getPB()) == '\n') {
+      if (f->putPB(f->getPB()) == '\n')
 	(void)f->getPB();
-      }
-    } else {
-      /*
-       *  write any error messages out to the user
-       */
+    }
+    else {
+      /* Write any error messages out to the user. */
       fputc(f->getPB(), stderr);
     }
   }
-  
+
   listOfImages.createImages();
   if (show_progress) {
     fprintf(stderr, "done\n");
@@ -1035,84 +1132,97 @@ static void generateImages (char *regionFileName)
 }
 
 /*
- *  replaceFd - replace a file descriptor, was, with, willbe.
+ *  set_redirection - Set up I/O Redirection for handle, was, to refer to
+ *                    stream on handle, willbe.
  */
 
-static void replaceFd (int was, int willbe)
+static void set_redirection(int was, int willbe)
 {
-  int dupres;
-
+  // Nothing to do if `was' and `willbe' already have same handle.
   if (was != willbe) {
-    if (close(was)<0) {
-      sys_fatal("close");
+    // Otherwise attempt the specified redirection.
+    if (dup2 (willbe, was) < 0) {
+      // Redirection failed, so issue diagnostic and bail out.
+      fprintf(stderr, "failed to replace fd=%d with %d\n", was, willbe);
+      if (willbe == STDOUT_FILENO)
+	fprintf(stderr,
+		"likely that stdout should be opened before %d\n", was);
+      sys_fatal("dup2");
     }
-    dupres = dup(willbe);
-    if (dupres != was) {
-      sys_fatal("dup");
-      fprintf(stderr, "trying to replace fd=%d with %d dup used %d\n", was, willbe, dupres);
-      if (willbe == 1) {
-	fprintf(stderr, "likely that stdout should be opened before %d\n", was);
-      }
-      exit(1);
-    }
-    if (close(willbe) < 0) {
+
+    // When redirection has been successfully completed assume redundant
+    // handle `willbe' is no longer required, so close it.
+    if (close(willbe) < 0)
+      // Issue diagnostic if `close' fails.
       sys_fatal("close");
-    }
   }
 }
 
 /*
- *  waitForChild - waits for child, pid, to exit.
+ *  save_and_redirect - Get duplicate handle for stream, was, then
+ *                      redirect, was, to refer to, willbe.
  */
 
-static void waitForChild (PID_T pid)
+static int save_and_redirect(int was, int willbe)
 {
-  PID_T waitpd;
-  int   status;
+  if (was == willbe)
+    // No redirection specified so don't do anything but silently bailing out.
+    return (was);
+
+  // Proceeding with redirection so first save and verify our duplicate
+  // handle for `was'.
+  int saved = dup(was);
+  if (saved < 0) {
+    fprintf(stderr, "unable to get duplicate handle for %d\n", was);
+    sys_fatal("dup");
+  }
 
-  waitpd = WAIT(&status, pid, _WAIT_CHILD);
-  if (waitpd != pid)
-    sys_fatal("wait");
+  // Duplicate handle safely established so complete redirection.
+  set_redirection(was, willbe);
+
+  // Finally return the saved duplicate descriptor for the
+  // original `was' stream.
+  return saved;
 }
 
 /*
- *  alterDeviceTo - if toImage is set then the arg list is altered to include
+ *  alterDeviceTo - If, toImage, is set
+ *                     the argument list is altered to include
  *                     IMAGE_DEVICE and we invoke groff rather than troff.
- *                  else 
- *                     set -Thtml and groff
+ *                  Else
+ *                     set -Thtml and groff.
  */
 
-static void alterDeviceTo (int argc, char *argv[], int toImage)
+static void alterDeviceTo(int argc, char *argv[], int toImage)
 {
-  int i=0;
+  int i = 0;
 
   if (toImage) {
     while (i < argc) {
-      if (strcmp(argv[i], "-Thtml") == 0) {
-	argv[i] = IMAGE_DEVICE;
-      }
+      if (strcmp(argv[i], "-Thtml") == 0)
+	argv[i] = (char *)IMAGE_DEVICE;
       i++;
     }
-    argv[troff_arg] = "groff";  /* rather than troff */
-  } else {
+    argv[troff_arg] = (char *)"groff";	/* rather than troff */
+  }
+  else {
     while (i < argc) {
-      if (strcmp(argv[i], IMAGE_DEVICE) == 0) {
-	argv[i] = "-Thtml";
-      }
+      if (strcmp(argv[i], IMAGE_DEVICE) == 0)
+	argv[i] = (char *)"-Thtml";
       i++;
     }
-    argv[troff_arg] = "groff";   /* use groff -Z */
+    argv[troff_arg] = (char *)"groff";	/* use groff -Z */
   }
 }
 
 /*
- *  addZ - appends -Z onto the command list for groff.
+ *  addZ - Append -Z onto the command list for groff.
  */
 
-char **addZ (int argc, char *argv[])
+char **addZ(int argc, char *argv[])
 {
-  char **new_argv = (char **)malloc((argc+2)*sizeof(char *));
-  int    i=0;
+  char **new_argv = (char **)malloc((argc + 2) * sizeof(char *));
+  int i = 0;
 
   if (new_argv == NULL)
     sys_fatal("malloc");
@@ -1121,9 +1231,9 @@ char **addZ (int argc, char *argv[])
     new_argv[i] = argv[i];
     i++;
   }
-  new_argv[i] = "-Z";
-  while (i<argc) {
-    new_argv[i+1] = argv[i];
+  new_argv[i] = (char *)"-Z";
+  while (i < argc) {
+    new_argv[i + 1] = argv[i];
     i++;
   }
   argc++;
@@ -1132,18 +1242,19 @@ char **addZ (int argc, char *argv[])
 }
 
 /*
- *  addRegDef - appends a defined register or string onto the command list for troff.
+ *  addRegDef - Append a defined register or string onto the command
+ *              list for troff.
  */
 
-char **addRegDef (int argc, char *argv[], const char *numReg)
+char **addRegDef(int argc, char *argv[], const char *numReg)
 {
-  char **new_argv = (char **)malloc((argc+2)*sizeof(char *));
-  int    i=0;
+  char **new_argv = (char **)malloc((argc + 2) * sizeof(char *));
+  int i = 0;
 
   if (new_argv == NULL)
     sys_fatal("malloc");
 
-  while (i<argc) {
+  while (i < argc) {
     new_argv[i] = argv[i];
     i++;
   }
@@ -1154,94 +1265,213 @@ char **addRegDef (int argc, char *argv[], const char *numReg)
 }
 
 /*
- *  dump_args - display the argument list.
+ *  dump_args - Display the argument list.
  */
 
-void dump_args (int argc, char *argv[])
+void dump_args(int argc, char *argv[])
 {
   fprintf(stderr, "  %d arguments:", argc);
-  for (int i=0; i<argc; i++)
+  for (int i = 0; i < argc; i++)
     fprintf(stderr, " %s", argv[i]);
   fprintf(stderr, "\n");
 }
 
+int char_buffer::run_output_filter(int filter, int /* argc */, char **argv)
+{
+  int pipedes[2];
+  PID_T child_pid;
+  int status;
+
+  if (pipe(pipedes) < 0)
+    sys_fatal("pipe");
+
+#if MAY_FORK_CHILD_PROCESS
+  // This is the UNIX process model.  To invoke our post-processor,
+  // we must `fork' the current process.
+
+  if ((child_pid = fork()) < 0)
+    sys_fatal("fork");
+
+  else if (child_pid == 0) {
+    // This is the child process fork.  We redirect its `stdin' stream
+    // to read data emerging from our pipe.  There is no point in saving,
+    // since we won't be able to restore later!
+
+    set_redirection(STDIN_FILENO, pipedes[0]);
+
+    // The parent process will be writing this data, so we should release
+    // the child's writeable handle on the pipe, since we have no use for it.
+
+    if (close(pipedes[1]) < 0)
+      sys_fatal("close");
+
+    // The IMAGE_OUTPUT_FILTER needs special output redirection...
+
+    if (filter == IMAGE_OUTPUT_FILTER) {
+      // with BOTH `stdout' AND `stderr' diverted to files.
+
+      set_redirection(STDOUT_FILENO, PS_OUTPUT_STREAM);
+      set_redirection(STDERR_FILENO, REGION_OUTPUT_STREAM);
+    }
+
+    // Now we are ready to launch the output filter.
+
+    execvp(argv[0], argv);
+
+    // If we get to here then the `exec...' request for the output filter
+    // failed.  Diagnose it and bail out.
+
+    error("couldn't exec %1: %2", argv[0], strerror(errno), ((char *)0));
+    fflush(stderr);	// just in case error() didn't
+    exit(1);
+  }
+
+  else {
+    // This is the parent process fork.  We will be writing data to the
+    // filter pipeline, and the child will be reading it.  We have no further
+    // use for our read handle on the pipe, and should close it.
+
+    if (close(pipedes[0]) < 0)
+      sys_fatal("close");
+
+    // Now we redirect the `stdout' stream to the inlet end of the pipe,
+    // and push out the appropiately formatted data to the filter.
+
+    pipedes[1] = save_and_redirect(STDOUT_FILENO, pipedes[1]);
+    emit_troff_output(DEVICE_FORMAT(filter));
+
+    // After emitting all the data we close our connection to the inlet
+    // end of the pipe so the child process will detect end of data.
+
+    set_redirection(STDOUT_FILENO, pipedes[1]);
+
+    // Finally, we must wait for the child process to complete.
+
+    if (WAIT(&status, child_pid, _WAIT_CHILD) != child_pid)
+      sys_fatal("wait");
+  }
+
+#elif MAY_SPAWN_ASYNCHRONOUS_CHILD
+
+  // We do not have `fork', (or we prefer not to use it),
+  // but asynchronous processes are allowed, passing data through pipes.
+  // This should be ok for most Win32 systems and is preferred to `fork'
+  // for starting child processes under Cygwin.
+
+  // Before we start the post-processor we bind its inherited `stdin'
+  // stream to the readable end of our pipe, saving our own `stdin' stream
+  // in `pipedes[0]'.
+
+  pipedes[0] = save_and_redirect(STDIN_FILENO, pipedes[0]);
+
+  // for the Win32 model,
+  // we need special provision for saving BOTH `stdout' and `stderr'.
+
+  int saved_stdout = dup(STDOUT_FILENO);
+  int saved_stderr = STDERR_FILENO;
+
+  // The IMAGE_OUTPUT_FILTER needs special output redirection...
+
+  if (filter == IMAGE_OUTPUT_FILTER) {
+    // with BOTH `stdout' AND `stderr' diverted to files while saving a
+    // duplicate handle for `stderr'.
+
+    set_redirection(STDOUT_FILENO, PS_OUTPUT_STREAM);
+    saved_stderr = save_and_redirect(STDERR_FILENO, REGION_OUTPUT_STREAM);
+  }
+
+  // We then use an asynchronous spawn request to start the post-processor.
+
+  if ((child_pid = spawnvp(_P_NOWAIT, argv[0], argv)) < 0) {
+    // Should the spawn request fail we issue a diagnostic and bail out.
+
+    error("cannot spawn %1: %2", argv[0], strerror(errno), ((char *)0));
+    exit(1);
+  }
+
+  // Once the post-processor has been started we revert our `stdin'
+  // to its original saved source, which also closes the readable handle
+  // for the pipe.
+
+  set_redirection(STDIN_FILENO, pipedes[0]);
+
+  // if we redirected `stderr', for use by the image post-processor,
+  // then we also need to reinstate its original assignment.
+
+  if (filter == IMAGE_OUTPUT_FILTER)
+    set_redirection(STDERR_FILENO, saved_stderr);
+
+  // Now we redirect the `stdout' stream to the inlet end of the pipe,
+  // and push out the appropiately formatted data to the filter.
+
+  set_redirection(STDOUT_FILENO, pipedes[1]);
+  emit_troff_output(DEVICE_FORMAT(filter));
+
+  // After emitting all the data we close our connection to the inlet
+  // end of the pipe so the child process will detect end of data.
+
+  set_redirection(STDOUT_FILENO, saved_stdout);
+
+  // And finally, we must wait for the child process to complete.
+
+  if (WAIT(&status, child_pid, _WAIT_CHILD) != child_pid)
+    sys_fatal("wait");
+
+#else /* can't do asynchronous pipes! */
+
+  // TODO: code to support an MS-DOS style process model
+  //        should go here
+
+#endif /* MAY_FORK_CHILD_PROCESS or MAY_SPAWN_ASYNCHRONOUS_CHILD */
+
+  return 0;
+}
+
 /*
- *  do_html - sets the troff number htmlflip and
- *            writes out the buffer to troff -Thtml
+ *  do_html - Set the troff number htmlflip and
+ *            write out the buffer to troff -Thtml.
  */
 
 int char_buffer::do_html(int argc, char *argv[])
 {
-  int pdes[2];
-  PID_T pid;
   string s;
 
   alterDeviceTo(argc, argv, 0);
-  argv += troff_arg;   // skip all arguments up to groff
+  argv += troff_arg;		// skip all arguments up to groff
   argc -= troff_arg;
   argv = addZ(argc, argv);
   argc++;
 
   s = "-dwww-image-template=";
-  s += macroset_template;   // do not combine these statements otherwise they will not work
-  s += '\0';                // the trailing '\0' is ignored
+  s += macroset_template;	// do not combine these statements,
+				// otherwise they will not work
+  s += '\0';                	// the trailing `\0' is ignored
   argv = addRegDef(argc, argv, s.contents());
   argc++;
 
-  if (pipe(pdes) < 0)
-    sys_fatal("pipe");
-
-  pid = fork();
-  if (pid < 0)
-    sys_fatal("fork");
-
-  if (pid == 0) {
-    // child
-    replaceFd(0, pdes[0]);
-    // close end we are not using
-    if (close(pdes[1])<0)
-      sys_fatal("close");
-    replaceFd(1, copyofstdoutfd); // and restore stdout
-
-    execvp(argv[0], argv);
-    error("couldn't exec %1: %2", argv[0], strerror(errno), (char *)0);
-    fflush(stderr);		/* just in case error() doesn't */
-    exit(1);
-  } else {
-    // parent
-
 #if defined(DEBUGGING)
-    /*
-     *  slight security risk so only enabled if compiled with defined(DEBUGGING)
-     */
-    if (debug) {
-      replaceFd(1, creat(htmlFileName, S_IWUSR|S_IRUSR));
-      write_file_html();
-    }
+# define HTML_DEBUG_STREAM  OUTPUT_STREAM(htmlFileName)
+  // slight security risk so only enabled if compiled with defined(DEBUGGING)
+  if (debug) {
+    int saved_stdout = save_and_redirect(STDOUT_FILENO, HTML_DEBUG_STREAM);
+    emit_troff_output(DEVICE_FORMAT(HTML_OUTPUT_FILTER));
+    set_redirection(STDOUT_FILENO, saved_stdout);
+  }
 #endif
-    replaceFd(1, pdes[1]);
-    // close end we are not using
-    if (close(pdes[0])<0)
-      sys_fatal("close");
 
-    write_file_html();
-    waitForChild(pid);
-  }
-  return 0;
+  return run_output_filter(HTML_OUTPUT_FILTER, argc, argv);
 }
 
 /*
- *  do_image - writes out the buffer to troff -Tps
+ *  do_image - Write out the buffer to troff -Tps.
  */
 
 int char_buffer::do_image(int argc, char *argv[])
 {
-  PID_T pid;
-  int pdes[2];
   string s;
 
   alterDeviceTo(argc, argv, 1);
-  argv += troff_arg;   // skip all arguments up to troff/groff
+  argv += troff_arg;		// skip all arguments up to troff/groff
   argc -= troff_arg;
   argv = addRegDef(argc, argv, "-rps4html=1");
   argc++;
@@ -1256,69 +1486,52 @@ int char_buffer::do_image(int argc, char *argv[])
   argv = addRegDef(argc, argv, "-P-pletter");
   argc++;
 
-  if (pipe(pdes) < 0)
-    sys_fatal("pipe");
-
-  pid = fork();
-  if (pid == 0) {
-    // child
-
-    int psFd     = creat(psFileName,     S_IWUSR|S_IRUSR);
-    int regionFd = creat(regionFileName, S_IWUSR|S_IRUSR);
-
-    replaceFd(1, psFd);
-    replaceFd(0, pdes[0]);
-    replaceFd(2, regionFd);
-
-    // close end we are not using
-    if (close(pdes[1])<0)
-      sys_fatal("close");
-
-    execvp(argv[0], argv);
-    error("couldn't exec %1: %2", argv[0], strerror(errno), (char *)0);
-    fflush(stderr);		/* just in case error() doesn't */
-    exit(1);
-  } else {
-    // parent
-
 #if defined(DEBUGGING)
-    /*
-     *  slight security risk so only enabled if compiled with defined(DEBUGGING)
-     */
-    if (debug) {
-      replaceFd(1, creat(troffFileName, S_IWUSR|S_IRUSR));
-      write_file_troff();
-    }
-#endif
-    replaceFd(1, pdes[1]);
-    write_file_troff();
-    waitForChild(pid);
+# define IMAGE_DEBUG_STREAM  OUTPUT_STREAM(troffFileName)
+  // slight security risk so only enabled if compiled with defined(DEBUGGING)
+  if (debug) {
+    int saved_stdout = save_and_redirect(STDOUT_FILENO, IMAGE_DEBUG_STREAM);
+    emit_troff_output(DEVICE_FORMAT(IMAGE_OUTPUT_FILTER));
+    set_redirection(STDOUT_FILENO, saved_stdout);
   }
-  return 0;
+#endif
+
+  return run_output_filter(IMAGE_OUTPUT_FILTER, argc, argv);
 }
 
 static char_buffer inputFile;
 
-
 /*
- *  usage - emit usage arguments.
+ *  usage - Emit usage arguments.
  */
 
-void usage(FILE *stream)
+static void usage(FILE *stream)
 {
-  fprintf(stream, "usage: %s troffname [-Iimage_name] [-Dimage_directory] [-P-o vertical_image_offset] [-P-i image_resolution] [troff flags] [files]\n", program_name);
-  fprintf(stream, "    vertical_image_offset (default %d/72 of an inch)\n", vertical_offset);
-  fprintf(stream, "    image_resolution (default %d) pixels per inch\n", image_res);
-  fprintf(stream, "    image_name is the name of the stem for all images (default is grohtml-<pid>)\n");
-  fprintf(stream, "    place all png files into image_directory\n");
+  fprintf(stream,
+	  "usage: %s troffname [-Iimage_name] [-Dimage_directory]\n"
+	  "       [-P-o vertical_image_offset] [-P-i image_resolution]\n"
+	  "       [troff flags]\n",
+	  program_name);
+  fprintf(stream,
+	  "    vertical_image_offset (default %d/72 of an inch)\n",
+	  vertical_offset);
+  fprintf(stream,
+	  "    image_resolution (default %d) pixels per inch\n",
+	  image_res);
+  fprintf(stream,
+	  "    image_name is the name of the stem for all images\n"
+	  "    (default is grohtml-<pid>)\n");
+  fprintf(stream,
+	  "    place all png files into image_directory\n");
 }
 
 /*
- *  scanArguments - scans for all arguments including -P-i, -P-o, -P-D and -P-I. It returns
- *                  the argument index of the first non option.
+ *  scanArguments - Scan for all arguments including -P-i, -P-o, -P-D,
+ *                  and -P-I.  Return the argument index of the first
+ *                  non-option.
  */
 
-int scanArguments (int argc, char **argv)
+static int scanArguments(int argc, char **argv)
 {
   const char *command_prefix = getenv("GROFF_COMMAND_PREFIX");
   if (!command_prefix)
@@ -1332,40 +1545,57 @@ int scanArguments (int argc, char **argv)
     { "version", no_argument, 0, 'v' },
     { NULL, 0, 0, 0 }
   };
-  while ((c = getopt_long(argc, argv, "+a:g:o:i:I:D:F:vbdhlrnp", long_options, NULL))
+  while ((c = getopt_long(argc, argv, "+a:bdD:F:g:hi:I:j:lno:prs:S:v",
+			  long_options, NULL))
 	 != EOF)
     switch(c) {
-    case 'v':
-      printf("GNU pre-grohtml (groff) version %s\n", Version_string);
-      exit(0);
     case 'a':
-      textAlphaBits = min(max(MIN_ALPHA_BITS, atoi(optarg)), MAX_ALPHA_BITS);
+      textAlphaBits = min(max(MIN_ALPHA_BITS, atoi(optarg)),
+			  MAX_ALPHA_BITS);
       if (textAlphaBits == 3) {
 	error("cannot use 3 bits of antialiasing information");
 	exit(1);
       }
       break;
+    case 'b':
+      // handled by post-grohtml (set background color to white)
+      break;
+    case 'd':
+#if defined(DEBUGGING)
+      debug = TRUE;
+#endif
+      break;
+    case 'D':
+      image_dir = optarg;
+      break;
+    case 'F':
+      font_path.command_line_dir(optarg);
+      break;
     case 'g':
-      graphicAlphaBits = min(max(MIN_ALPHA_BITS, atoi(optarg)), MAX_ALPHA_BITS);
+      graphicAlphaBits = min(max(MIN_ALPHA_BITS, atoi(optarg)),
+			     MAX_ALPHA_BITS);
       if (graphicAlphaBits == 3) {
 	error("cannot use 3 bits of antialiasing information");
 	exit(1);
       }
       break;
-    case 'b':
-      // handled by post-grohtml (set background color to white)
+    case 'h':
+      // handled by post-grohtml
       break;
-    case 'D':
-      image_dir = optarg;
+    case 'i':
+      image_res = atoi(optarg);
       break;
     case 'I':
       image_template = optarg;
       break;
-    case 'i':
-      image_res = atoi(optarg);
+    case 'j':
+      // handled by post-grohtml (set job name for multiple file output)
       break;
-    case 'F':
-      font_path.command_line_dir(optarg);
+    case 'l':
+      // handled by post-grohtml (no automatic section links)
+      break;
+    case 'n':
+      // handled by post-grohtml (generate simple heading anchors)
       break;
     case 'o':
       vertical_offset = atoi(optarg);
@@ -1373,14 +1603,18 @@ int scanArguments (int argc, char **argv)
     case 'p':
       show_progress = TRUE;
       break;
-    case 'd':
-#if defined(DEBUGGING)
-      debug = TRUE;
-#endif
+    case 'r':
+      // handled by post-grohtml (no header and footer lines)
       break;
-    case 'h':
-      // handled by post-grohtml
+    case 's':
+      // handled by post-grohtml (use font size n as the html base font size)
+      break;
+    case 'S':
+      // handled by post-grohtml (set file split level)
       break;
+    case 'v':
+      printf("GNU pre-grohtml (groff) version %s\n", Version_string);
+      exit(0);
     case CHAR_MAX + 1: // --help
       usage(stdout);
       exit(0);
@@ -1407,19 +1641,19 @@ int scanArguments (int argc, char **argv)
 }
 
 /*
- *  makeTempFiles - name the temporary files
+ *  makeTempFiles - Name the temporary files.
  */
 
-static int makeTempFiles (void)
+static int makeTempFiles(void)
 {
 #if defined(DEBUGGING)
-  psFileName     = "/tmp/prehtml-ps";
-  regionFileName = "/tmp/prehtml-region";
-  imagePageName  = "/tmp/prehtml-page";
-  psPageName     = "/tmp/prehtml-psn";
-  troffFileName  = "/tmp/prehtml-troff";
-  htmlFileName   = "/tmp/prehtml-html";
-#else
+  psFileName = DEBUG_FILE("prehtml-ps");
+  regionFileName = DEBUG_FILE("prehtml-region");
+  imagePageName = DEBUG_FILE("prehtml-page");
+  psPageName = DEBUG_FILE("prehtml-psn");
+  troffFileName = DEBUG_FILE("prehtml-troff");
+  htmlFileName = DEBUG_FILE("prehtml-html");
+#else /* not DEBUGGING */
   FILE *f;
 
   /* psPageName contains a single page of postscript */
@@ -1462,7 +1696,7 @@ static int makeTempFiles (void)
   }
   fclose(f);
 
-#endif
+#endif /* not DEBUGGING */
   return 0;
 }
 
@@ -1470,9 +1704,27 @@ int main(int argc, char **argv)
 {
   program_name = argv[0];
   int i;
-  int found=0;
-  int ok=1;
-
+  int found = 0;
+  int ok = 1;
+
+#ifdef CAPTURE_MODE
+  FILE *dump;
+  fprintf(stderr, "%s: invoked with %d arguments ...\n", argv[0], argc);
+  for (i = 0; i < argc; i++)
+    fprintf(stderr, "%2d: %s\n", i, argv[i]);
+  if ((dump = fopen(DEBUG_FILE("pre-html-data"), "wb")) != NULL) {
+    while((i = fgetc(stdin)) >= 0)
+      fputc(i, dump);
+    fclose(dump);
+  }
+  exit(1);
+#endif /* CAPTURE_MODE */
+  device = "html";
+  if (!font::load_desc())
+    fatal("cannot find devhtml/DESC exiting");
+  image_gen = font::image_generator;
+  if (image_gen == NULL || (strcmp(image_gen, "") == 0))
+    fatal("devhtml/DESC must set the image_generator field, exiting");
   postscriptRes = get_resolution();
   i = scanArguments(argc, argv);
   setupAntiAlias();
@@ -1482,19 +1734,15 @@ int main(int argc, char **argv)
     if (argv[i][0] != '-') {
       /* found source file */
       ok = do_file(argv[i]);
-      if (! ok) {
-	return( 0 );
-      }
+      if (!ok)
+	return 0;
       found = 1;
     }
     i++;
   }
 
-  copyofstdoutfd=dup(stdoutfd);
-
-  if (! found) {
+  if (!found)
     do_file("-");
-  }
   if (makeTempFiles())
     return 1;
   ok = inputFile.do_image(argc, argv);
@@ -1510,9 +1758,9 @@ static int do_file(const char *filename)
   FILE *fp;
 
   current_filename = filename;
-  if (strcmp(filename, "-") == 0) {
+  if (strcmp(filename, "-") == 0)
     fp = stdin;
-  } else {
+  else {
     fp = fopen(filename, "r");
     if (fp == 0) {
       error("can't open `%1': %2", filename, strerror(errno));
@@ -1521,6 +1769,7 @@ static int do_file(const char *filename)
   }
 
   if (inputFile.read_file(fp)) {
+    // XXX
   }
 
   if (fp != stdin)
diff --git a/contrib/groff/src/preproc/html/pre-html.h b/contrib/groff/src/preproc/html/pre-html.h
index f9a590c17b7e..3eedb21c72bb 100644
--- a/contrib/groff/src/preproc/html/pre-html.h
+++ b/contrib/groff/src/preproc/html/pre-html.h
@@ -16,7 +16,7 @@ for more details.
 
 You should have received a copy of the GNU General Public License along
 with groff; see the file COPYING.  If not, write to the Free Software
-Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
 
 /*
  *  defines functions implemented within pre-html.c
diff --git a/contrib/groff/src/preproc/html/pushback.cpp b/contrib/groff/src/preproc/html/pushback.cpp
index 07a15e36fe87..b71558783508 100644
--- a/contrib/groff/src/preproc/html/pushback.cpp
+++ b/contrib/groff/src/preproc/html/pushback.cpp
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
      Written by Gaius Mulley (gaius@glam.ac.uk).
 
 This file is part of groff.
@@ -16,7 +16,7 @@ for more details.
 
 You should have received a copy of the GNU General Public License along
 with groff; see the file COPYING.  If not, write to the Free Software
-Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
 
 #include "lib.h"
 
@@ -83,14 +83,12 @@ pushBackBuffer::pushBackBuffer (char *filename)
 
 pushBackBuffer::~pushBackBuffer ()
 {
-  int old;
-
   if (charStack != 0) {
     free(charStack);
   }
   close(0);
   /* restore stdin in file descriptor 0 */
-  old = dup(stdIn);
+  dup(stdIn);
   close(stdIn);
 }
 
@@ -162,10 +160,8 @@ static int isWhite (char ch)
 
 void pushBackBuffer::skipToNewline (void)
 {
-  char ch;
-
   while ((putPB(getPB()) != '\n') && (! eofFound)) {
-    ch = getPB();
+    getPB();
   }
 }
 
@@ -274,15 +270,15 @@ int pushBackBuffer::readInt (void)
  *  convertToFloat - converts integers, a and b into a.b
  */
 
-static float convertToFloat (int a, int b)
+static double convertToFloat (int a, int b)
 {
   int c=10;
-  float f;
+  double f;
 
   while (b>c) {
     c *= 10;
   }
-  f = ((float)a) + (((float)b)/((float)c));
+  f = ((double)a) + (((double)b)/((double)c));
   return( f );
 }
 
@@ -290,7 +286,7 @@ static float convertToFloat (int a, int b)
  *  readNumber - returns a float representing the word just read.
  */
 
-float pushBackBuffer::readNumber (void)
+double pushBackBuffer::readNumber (void)
 {
   int i;
   char ch;
@@ -300,7 +296,7 @@ float pushBackBuffer::readNumber (void)
     return convertToFloat(i, readInt());
   }
   putPB(ch);
-  return (float)i;
+  return (double)i;
 }
 
 /*
@@ -312,7 +308,7 @@ float pushBackBuffer::readNumber (void)
 char *pushBackBuffer::readString (void)
 {
   char  buffer[MAXPUSHBACKSTACK];
-  char *string = 0;
+  char *str = 0;
   int   i=0;
   char ch=getPB();
 
@@ -326,8 +322,8 @@ char *pushBackBuffer::readString (void)
   }
   if (i < MAXPUSHBACKSTACK) {
     buffer[i] = (char)0;
-    string = (char *)malloc(strlen(buffer)+1);
-    strcpy(string, buffer);
+    str = (char *)malloc(strlen(buffer)+1);
+    strcpy(str, buffer);
   }
-  return( string );
+  return( str );
 }
diff --git a/contrib/groff/src/preproc/html/pushback.h b/contrib/groff/src/preproc/html/pushback.h
index 608bac53991e..3fddad66f11d 100644
--- a/contrib/groff/src/preproc/html/pushback.h
+++ b/contrib/groff/src/preproc/html/pushback.h
@@ -1,5 +1,5 @@
 // -*- C -*-
-/* Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
      Written by Gaius Mulley (gaius@glam.ac.uk).
 
 This file is part of groff.
@@ -16,7 +16,7 @@ for more details.
 
 You should have received a copy of the GNU General Public License along
 with groff; see the file COPYING.  If not, write to the Free Software
-Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
 
 
 #define eof              (char)-1
@@ -39,16 +39,16 @@ class pushBackBuffer
   int         stdIn;
 
  public:
-        pushBackBuffer (char *);
-  ~     pushBackBuffer ();
-  char  getPB          (void);
-  char  putPB          (char ch);
-  void  skipUntilToken (void);
-  void  skipToNewline  (void);
-  float readNumber     (void);
-  int   readInt        (void);
-  char *readString     (void);
-  int   isString       (const char *string);
+         pushBackBuffer (char *);
+  ~      pushBackBuffer ();
+  char   getPB          (void);
+  char   putPB          (char ch);
+  void   skipUntilToken (void);
+  void   skipToNewline  (void);
+  double readNumber     (void);
+  int    readInt        (void);
+  char  *readString     (void);
+  int    isString       (const char *string);
 };