diff3: fix merge mode

Make the merge mode compatible with GNU diff3
Add tests for all the changes, those tests are extracted from the
etcupdate testsuite.

This version passes the etcupdate testsuite and the diffutils diff3
test suite.

MFC After:	1 week

15 files changed, 168 insertions, 30 deletions

diff --git a/usr.bin/diff3/diff3.c b/usr.bin/diff3/diff3.c
index 4f3239b10625..9a01951e60ab 100644
--- a/usr.bin/diff3/diff3.c
+++ b/usr.bin/diff3/diff3.c
@@ -150,7 +150,7 @@ static void repos(int);
 static void separate(const char *);
 static void edscript(int) __dead2;
 static void Ascript(int) __dead2;
-static void mergescript(int) __dead2;
+static void mergescript(int, int) __dead2;
 static void increase(void);
 static void usage(void);
 static void printrange(FILE *, struct range *);
@@ -361,12 +361,13 @@ merge(int m1, int m2)
 {
 	struct diff *d1, *d2, *d3;
 	int j, t1, t2;
+	int f1f3delta;
 	bool dup = false;
 
 	d1 = d13;
 	d2 = d23;
 	j = 0;
-	int f1f3delta = 0;
+	f1f3delta = 0;
 
 	for (;;) {
 		t1 = (d1 < d13 + m1);
@@ -382,6 +383,12 @@ merge(int m1, int m2)
 				change(1, &d1->old, false);
 				keep(2, &d1->new);
 				change(3, &d1->new, false);
+			} else if (mflag) {
+				j++;
+				de[j].type = DIFF_TYPE1;
+				de[j].old = d1->old;
+				de[j].new = d1->new;
+				overlap[j] = 0;
 			} else if (eflag == EFLAG_OVERLAP) {
 				j = edit(d2, dup, j, DIFF_TYPE1);
 			}
@@ -437,6 +444,14 @@ merge(int m1, int m2)
 				change(2, &d2->old, false);
 				d3 = d1->old.to > d1->old.from ? d1 : d2;
 				change(3, &d3->new, false);
+			} else if (mflag) {
+				j++;
+				de[j].type = DIFF_TYPE3;
+				de[j].old = d1->old;
+				de[j].new = d1->new;
+				overlap[j] = !dup;
+				if (!dup)
+					overlapcnt++;
 			} else {
 				j = edit(d1, dup, j, DIFF_TYPE3);
 			}
@@ -468,7 +483,7 @@ merge(int m1, int m2)
 	}
 
 	if (mflag)
-		mergescript(j);
+		mergescript(j, f1f3delta);
 	else if (Aflag)
 		Ascript(j);
 	else if (eflag)
@@ -701,7 +716,7 @@ edscript(int n)
 	if (iflag)
 		printf("w\nq\n");
 
-	exit(eflag == EFLAG_NONE ? overlapcnt : 0);
+	exit(oflag ? overlapcnt > 0 : 0);
 }
 
 /*
@@ -795,11 +810,10 @@ Ascript(int n)
  * inbetween lines.
  */
 static void
-mergescript(int i)
+mergescript(int i, int f1f3delta)
 {
 	struct range r, *new, *old;
 	int n;
-	bool delete = false;
 
 	r.from = 1;
 	r.to = 1;
@@ -812,13 +826,9 @@ mergescript(int i)
 		 * Print any lines leading up to here. If we are merging don't
 		 * print deleted ranges.
 		 */
-		delete = (new->from == new->to);
-		if (de[n].type == DIFF_TYPE1 && delete)
-			r.to = new->from - 1;
-		else if (de[n].type == DIFF_TYPE3 && (old->from == old->to)) {
-			r.from = old->from - 1;
-			r.to = new->from;
-		} else if (de[n].type == DIFF_TYPE2)
+		if (de[n].type == DIFF_TYPE1)
+			r.to = old->to;
+		else if (de[n].type == DIFF_TYPE2)
 			r.to = new->from + de_delta[n];
 		else
 			r.to = old->from;
@@ -826,9 +836,7 @@ mergescript(int i)
 		printrange(fp[0], &r);
 		switch (de[n].type) {
 		case DIFF_TYPE1:
-			/* If this isn't a delete print it */
-			if (!delete)
-				printrange(fp[2], new);
+			/* Content included in "between" printing from fp[0] */
 			break;
 		case DIFF_TYPE2:
 			printf("%s %s\n", oldmark, f2mark);
@@ -870,8 +878,6 @@ mergescript(int i)
 
 		if (de[n].type == DIFF_TYPE2)
 			r.from = new->to + de_delta[n];
-		else if (old->from == old->to)
-			r.from = new->to;
 		else
 			r.from = old->to;
 	}
@@ -879,18 +885,11 @@ mergescript(int i)
 	/*
 	 * Print from the final range to the end of 'myfile'. Any deletions or
 	 * additions to this file should have been handled by now.
-	 *
-	 * If the ranges are the same we need to rewind a line.
-	 * If the new range is 0 length (from == to), we need to use the new
-	 * range.
 	 */
 	new = &de[n-1].new;
 	old = &de[n-1].old;
 
-	if (old->from == new->from && old->to == new->to)
-		r.from--;
-	else if (new->from == new->to)
-		r.from = new->from;
+	r.from -= f1f3delta;
 
 	r.to = INT_MAX;
 	printrange(fp[2], &r);
diff --git a/usr.bin/diff3/tests/Makefile b/usr.bin/diff3/tests/Makefile
index 864f27beede8..e35ab095f2f7 100644
--- a/usr.bin/diff3/tests/Makefile
+++ b/usr.bin/diff3/tests/Makefile
@@ -23,6 +23,20 @@ ${PACKAGE}FILES+=	\
 	long-A.out \
 	long-merge.out \
 	fbsdid1.txt \
-	fbsdid2.txt
+	fbsdid2.txt \
+	conflict1.txt \
+	conflict2.txt \
+	conflict3.txt \
+	conflict-merge.out \
+	simple1.txt \
+	simple2.txt \
+	simple3.txt \
+	simple-merge.out \
+	simple-Em.out \
+	conflict-Em.out \
+	passwd-test.txt \
+	passwd-old.txt \
+	passwd-new.txt \
+	passwd-Em.out
 
 .include <bsd.test.mk>
diff --git a/usr.bin/diff3/tests/conflict1.txt b/usr.bin/diff3/tests/conflict1.txt
new file mode 100644
index 000000000000..d5bde7598f68
--- /dev/null
+++ b/usr.bin/diff3/tests/conflict1.txt
@@ -0,0 +1,5 @@
+# root: me@my.domain
+
+# Basic system aliases -- these MUST be present
+MAILER-DAEMON: postmaster
+postmaster: root
diff --git a/usr.bin/diff3/tests/conflict2.txt b/usr.bin/diff3/tests/conflict2.txt
new file mode 100644
index 000000000000..9afb26959e35
--- /dev/null
+++ b/usr.bin/diff3/tests/conflict2.txt
@@ -0,0 +1,9 @@
+#root:me@my.domain
+
+#Basicsystemaliases--theseMUSTbepresent
+MAILER-DAEMON:postmaster
+postmaster:root
+
+#Generalredirectionsforpseudoaccounts
+_dhcp:root
+_pflogd:root
diff --git a/usr.bin/diff3/tests/conflict3.txt b/usr.bin/diff3/tests/conflict3.txt
new file mode 100644
index 000000000000..14ac33b41853
--- /dev/null
+++ b/usr.bin/diff3/tests/conflict3.txt
@@ -0,0 +1,5 @@
+root:someone@example.com
+
+#Basicsystemaliases--theseMUSTbepresent
+MAILER-DAEMON:postmaster
+postmaster:root
diff --git a/usr.bin/diff3/tests/diff3_test.sh b/usr.bin/diff3/tests/diff3_test.sh
index 3cbd7dac1ed9..4510653bcd47 100755
--- a/usr.bin/diff3/tests/diff3_test.sh
+++ b/usr.bin/diff3/tests/diff3_test.sh
@@ -5,6 +5,11 @@ atf_test_case diff3_ed
 atf_test_case diff3_A
 atf_test_case diff3_merge
 atf_test_case diff3_E_merge
+atf_test_case diff3_merge_conflict
+atf_test_case diff3_merge_simple
+atf_test_case diff3_Em_simple
+atf_test_case diff3_Em_conflict
+atf_test_case diff3_Em_insert
 
 diff3_body()
 {
@@ -20,10 +25,10 @@ diff3_body()
 	atf_check -o file:$(atf_get_srcdir)/2.out \
 		diff3 -e $(atf_get_srcdir)/1.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt
 
-	atf_check -o file:$(atf_get_srcdir)/3.out \
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/3.out \
 		diff3 -E -L 1 -L 2 -L 3 $(atf_get_srcdir)/1.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt
 
-	atf_check -o file:$(atf_get_srcdir)/4.out \
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/4.out \
 		diff3 -X -L 1 -L 2 -L 3 $(atf_get_srcdir)/1.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt
 
 	atf_check -o file:$(atf_get_srcdir)/5.out \
@@ -75,7 +80,6 @@ expected="<<<<<<< 2
 =======
 # \$FreeBSD: head/local 12345 jhb \$
 >>>>>>> 3
-# \$FreeBSD: head/local 12345 jhb \$
 
 this is a file
 
@@ -97,6 +101,36 @@ these are some local mods to the file
 }
 
 
+diff3_merge_conflict_body()
+{
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/conflict-merge.out \
+		diff3 -m -L conflict3.txt -L conflict1.txt -L conflict2.txt $(atf_get_srcdir)/conflict3.txt $(atf_get_srcdir)/conflict1.txt $(atf_get_srcdir)/conflict2.txt
+}
+
+diff3_merge_simple_body()
+{
+	atf_check -s exit:0 -o file:$(atf_get_srcdir)/simple-merge.out \
+		diff3 -m $(atf_get_srcdir)/simple3.txt $(atf_get_srcdir)/simple1.txt $(atf_get_srcdir)/simple2.txt
+}
+
+diff3_Em_simple_body()
+{
+	atf_check -s exit:0 -o file:$(atf_get_srcdir)/simple-Em.out \
+		diff3 -E -m $(atf_get_srcdir)/simple3.txt $(atf_get_srcdir)/simple1.txt $(atf_get_srcdir)/simple2.txt
+}
+
+diff3_Em_conflict_body()
+{
+	atf_check -s exit:1 -o file:$(atf_get_srcdir)/conflict-Em.out \
+		diff3 -E -m -L conflict3.txt -L conflict1.txt -L conflict2.txt $(atf_get_srcdir)/conflict3.txt $(atf_get_srcdir)/conflict1.txt $(atf_get_srcdir)/conflict2.txt
+}
+
+diff3_Em_insert_body()
+{
+	atf_check -s exit:0 -o file:$(atf_get_srcdir)/passwd-Em.out \
+		diff3 -E -m $(atf_get_srcdir)/passwd-test.txt $(atf_get_srcdir)/passwd-old.txt $(atf_get_srcdir)/passwd-new.txt
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case diff3
@@ -105,4 +139,9 @@ atf_init_test_cases()
 	atf_add_test_case diff3_A
 	atf_add_test_case diff3_merge
 	atf_add_test_case diff3_E_merge
+	atf_add_test_case diff3_merge_conflict
+	atf_add_test_case diff3_merge_simple
+	atf_add_test_case diff3_Em_simple
+	atf_add_test_case diff3_Em_conflict
+	atf_add_test_case diff3_Em_insert
 }
diff --git a/usr.bin/diff3/tests/passwd-Em.out b/usr.bin/diff3/tests/passwd-Em.out
new file mode 100644
index 000000000000..2b52a6440f6b
--- /dev/null
+++ b/usr.bin/diff3/tests/passwd-Em.out
@@ -0,0 +1,16 @@
+#
+root:<rpass>:0:0::0:0:Charlie &:/root:/bin/csh
+toor:*:0:0::0:0:Bourne-again Superuser:/root:
+daemon:*:1:1::0:0:Owner of many system processes:/root:/usr/sbin/nologin
+operator:*:2:5::0:0:System &:/:/usr/sbin/nologin
+_dhcp:*:65:65::0:0:dhcp programs:/var/empty:/usr/sbin/nologin
+uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/local/libexec/uucp/uucico
+pop:*:68:6::0:0:Post Office Owner:/nonexistent:/usr/sbin/nologin
+auditdistd:*:78:77::0:0:Auditdistd unprivileged user:/var/empty:/usr/sbin/nologin
+www:*:80:80::0:0:World Wide Web Owner:/nonexistent:/usr/sbin/nologin
+hast:*:845:845::0:0:HAST unprivileged user:/var/empty:/usr/sbin/nologin
+nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/usr/sbin/nologin
+john:<password>:1001:1001::0:0:John Baldwin:/home/john:/bin/tcsh
+messagebus:*:556:556::0:0:D-BUS Daemon User:/nonexistent:/usr/sbin/nologin
+polkit:*:562:562::0:0:PolicyKit User:/nonexistent:/usr/sbin/nologin
+haldaemon:*:560:560::0:0:HAL Daemon User:/nonexistent:/usr/sbin/nologin
diff --git a/usr.bin/diff3/tests/passwd-new.txt b/usr.bin/diff3/tests/passwd-new.txt
new file mode 100644
index 000000000000..8bec617219a3
--- /dev/null
+++ b/usr.bin/diff3/tests/passwd-new.txt
@@ -0,0 +1,12 @@
+#
+root::0:0::0:0:Charlie &:/root:/bin/csh
+toor:*:0:0::0:0:Bourne-again Superuser:/root:
+daemon:*:1:1::0:0:Owner of many system processes:/root:/usr/sbin/nologin
+operator:*:2:5::0:0:System &:/:/usr/sbin/nologin
+_dhcp:*:65:65::0:0:dhcp programs:/var/empty:/usr/sbin/nologin
+uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/local/libexec/uucp/uucico
+pop:*:68:6::0:0:Post Office Owner:/nonexistent:/usr/sbin/nologin
+auditdistd:*:78:77::0:0:Auditdistd unprivileged user:/var/empty:/usr/sbin/nologin
+www:*:80:80::0:0:World Wide Web Owner:/nonexistent:/usr/sbin/nologin
+hast:*:845:845::0:0:HAST unprivileged user:/var/empty:/usr/sbin/nologin
+nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/usr/sbin/nologin
diff --git a/usr.bin/diff3/tests/passwd-old.txt b/usr.bin/diff3/tests/passwd-old.txt
new file mode 100644
index 000000000000..7a6f936e90c9
--- /dev/null
+++ b/usr.bin/diff3/tests/passwd-old.txt
@@ -0,0 +1,11 @@
+#
+root::0:0::0:0:Charlie &:/root:/bin/csh
+toor:*:0:0::0:0:Bourne-again Superuser:/root:
+daemon:*:1:1::0:0:Owner of many system processes:/root:/usr/sbin/nologin
+operator:*:2:5::0:0:System &:/:/usr/sbin/nologin
+_dhcp:*:65:65::0:0:dhcp programs:/var/empty:/usr/sbin/nologin
+uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/local/libexec/uucp/uucico
+pop:*:68:6::0:0:Post Office Owner:/nonexistent:/usr/sbin/nologin
+www:*:80:80::0:0:World Wide Web Owner:/nonexistent:/usr/sbin/nologin
+hast:*:845:845::0:0:HAST unprivileged user:/var/empty:/usr/sbin/nologin
+nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/usr/sbin/nologin
diff --git a/usr.bin/diff3/tests/passwd-test.txt b/usr.bin/diff3/tests/passwd-test.txt
new file mode 100644
index 000000000000..f2b277fb3b4c
--- /dev/null
+++ b/usr.bin/diff3/tests/passwd-test.txt
@@ -0,0 +1,15 @@
+#
+root:<rpass>:0:0::0:0:Charlie &:/root:/bin/csh
+toor:*:0:0::0:0:Bourne-again Superuser:/root:
+daemon:*:1:1::0:0:Owner of many system processes:/root:/usr/sbin/nologin
+operator:*:2:5::0:0:System &:/:/usr/sbin/nologin
+_dhcp:*:65:65::0:0:dhcp programs:/var/empty:/usr/sbin/nologin
+uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/local/libexec/uucp/uucico
+pop:*:68:6::0:0:Post Office Owner:/nonexistent:/usr/sbin/nologin
+www:*:80:80::0:0:World Wide Web Owner:/nonexistent:/usr/sbin/nologin
+hast:*:845:845::0:0:HAST unprivileged user:/var/empty:/usr/sbin/nologin
+nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/usr/sbin/nologin
+john:<password>:1001:1001::0:0:John Baldwin:/home/john:/bin/tcsh
+messagebus:*:556:556::0:0:D-BUS Daemon User:/nonexistent:/usr/sbin/nologin
+polkit:*:562:562::0:0:PolicyKit User:/nonexistent:/usr/sbin/nologin
+haldaemon:*:560:560::0:0:HAL Daemon User:/nonexistent:/usr/sbin/nologin
diff --git a/usr.bin/diff3/tests/simple-Em.out b/usr.bin/diff3/tests/simple-Em.out
new file mode 100644
index 000000000000..c9ad1c1bed8f
--- /dev/null
+++ b/usr.bin/diff3/tests/simple-Em.out
@@ -0,0 +1,3 @@
+this is an new line
+
+this is a local line
diff --git a/usr.bin/diff3/tests/simple-merge.out b/usr.bin/diff3/tests/simple-merge.out
new file mode 100644
index 000000000000..c9ad1c1bed8f
--- /dev/null
+++ b/usr.bin/diff3/tests/simple-merge.out
@@ -0,0 +1,3 @@
+this is an new line
+
+this is a local line
diff --git a/usr.bin/diff3/tests/simple1.txt b/usr.bin/diff3/tests/simple1.txt
new file mode 100644
index 000000000000..4c4c2cd1a4e7
--- /dev/null
+++ b/usr.bin/diff3/tests/simple1.txt
@@ -0,0 +1,2 @@
+this is an old line
+
diff --git a/usr.bin/diff3/tests/simple2.txt b/usr.bin/diff3/tests/simple2.txt
new file mode 100644
index 000000000000..e880a8af5c39
--- /dev/null
+++ b/usr.bin/diff3/tests/simple2.txt
@@ -0,0 +1,2 @@
+this is an new line
+
diff --git a/usr.bin/diff3/tests/simple3.txt b/usr.bin/diff3/tests/simple3.txt
new file mode 100644
index 000000000000..4ab38534cba1
--- /dev/null
+++ b/usr.bin/diff3/tests/simple3.txt
@@ -0,0 +1,3 @@
+this is an old line
+
+this is a local line