stand: split fg/bg handling up a little further

These can be setup independently, so we should also check them and
initialize each independently.  This fixes a pre-existing bug where-in
we may not pickup a bg color specified in the environment if a fg color
wasn't set.

The new version also ensures that we're hooking the color vars properly
if we're using a value that was already there, as the console may need
to adjust if something wants to switch them up again.  Otherwise, a
teken.fg_color set in loader could conceivably occur that only changes
the color when you get to the kernel, which could be surprising.

Reviewed by:	imp

(cherry picked from commit 95e6fd1fd85a448d2c68473b85a61fba24c9bc4f)

1 files changed, 41 insertions, 16 deletions

diff --git a/stand/common/gfx_fb.c b/stand/common/gfx_fb.c
index 9aa0431a04d6..687c081a1d5d 100644
--- a/stand/common/gfx_fb.c
+++ b/stand/common/gfx_fb.c
@@ -223,35 +223,60 @@ gfx_parse_mode_str(char *str, int *x, int *y, int *depth)
 	return (true);
 }
 
+/*
+ * Returns true if we set the color from pre-existing environment, false if
+ * just used existing defaults.
+ */
+static bool
+gfx_fb_evalcolor(const char *envname, teken_color_t *cattr,
+    ev_sethook_t sethook, ev_unsethook_t unsethook)
+{
+	const char *ptr;
+	char env[10];
+	bool from_env = false;
+
+	ptr = getenv(envname);
+	if (ptr != NULL) {
+		*cattr = strtol(ptr, NULL, 10);
+
+		/*
+		 * If we can't unset the value, then it's probably hooked
+		 * properly and we can just carry on.  Otherwise, we want to
+		 * reinitialize it so that we can hook it for the console that
+		 * we're resetting defaults for.
+		 */
+		if (unsetenv(envname) != 0)
+			return (true);
+		from_env = true;
+	}
+
+	snprintf(env, sizeof(env), "%d", *cattr);
+	env_setenv(envname, EV_VOLATILE, env, sethook, unsethook);
+
+	return (from_env);
+}
+
 void
 gfx_fb_setcolors(teken_attr_t *attr, ev_sethook_t sethook,
      ev_unsethook_t unsethook)
 {
 	const char *ptr;
-	char env[10];
+	bool need_setattr = false;
 
 	/*
 	 * On first run, we setup an environment hook to process any color
 	 * changes.  If the env is already set, we pick up fg and bg color
 	 * values from the environment.
 	 */
-	ptr = getenv("teken.fg_color");
-	if (ptr != NULL) {
-		attr->ta_fgcolor = strtol(ptr, NULL, 10);
-		ptr = getenv("teken.bg_color");
-		attr->ta_bgcolor = strtol(ptr, NULL, 10);
+	if (gfx_fb_evalcolor("teken.fg_color", &attr->ta_fgcolor,
+	    sethook, unsethook))
+		need_setattr = true;
+	if (gfx_fb_evalcolor("teken.bg_color", &attr->ta_bgcolor,
+	    sethook, unsethook))
+		need_setattr = true;
 
+	if (need_setattr)
 		teken_set_defattr(&gfx_state.tg_teken, attr);
-	} else {
-		snprintf(env, sizeof(env), "%d",
-		    attr->ta_fgcolor);
-		env_setenv("teken.fg_color", EV_VOLATILE, env,
-		    sethook, unsethook);
-		snprintf(env, sizeof(env), "%d",
-		    attr->ta_bgcolor);
-		env_setenv("teken.bg_color", EV_VOLATILE, env,
-		    sethook, unsethook);
-	}
 }
 
 static uint32_t