bug 638: Save, set and restore the DISPLAY environment variable.

Thanks to this trick the appropriate handler is executed,
even in a mixed (X11, framebuffer) environment.

---
commit 65a3518a912d6cc6aa38cee4a4142299d7a25cc7
tree 47b6a1c4af22420fef498ac26dd0955e79428024
parent 81f8ee1fa2b94ef40460eb4a42710e1ed9e22c98
author Witold Filipczyk <witekfl@poczta.onet.pl> Sun, 16 Mar 2008 16:29:32 +0100
committer Witold Filipczyk <nobody@nowhere> Sun, 16 Mar 2008 16:29:32 +0100

 configure.in               |    1 +
 src/mime/backend/mailcap.c |   58 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 1 deletions(-)

diff --git a/configure.in b/configure.in
index 0a867ae..5cfeaa9 100644
--- a/configure.in
+++ b/configure.in
@@ -307,6 +307,7 @@ AC_CHECK_FUNCS(gettimeofday clock_gettime)
 AC_CHECK_FUNCS([cygwin_conv_to_full_win32_path])
 
 AC_CHECK_FUNCS(setenv putenv, HAVE_SETENV_OR_PUTENV=yes)
+AC_CHECK_FUNCS(unsetenv)
 AC_CHECK_FUNCS(getuid, HAVE_GETUID=yes)
 AC_CHECK_FUNCS(geteuid, HAVE_GETEUID=yes)
 
diff --git a/src/mime/backend/mailcap.c b/src/mime/backend/mailcap.c
index 76ea78b..70e270d 100644
--- a/src/mime/backend/mailcap.c
+++ b/src/mime/backend/mailcap.c
@@ -646,8 +646,57 @@ get_mailcap_entry(unsigned char *type)
 	return entry;
 }
 
+#if defined(HAVE_SETENV) || defined(HAVE_PUTENV)
+/* restore == 0 set DISPLAY
+ * restore == 1 restore DISPLAY
+ */
+static void
+set_display(int xwin, int restore)
+{
+	static unsigned char *display = NULL;
+
+	if (!restore) {
+		display = getenv("DISPLAY");
+		if (display) display = stracpy(display);
+		if (xwin) {
+#ifdef HAVE_SETENV
+			setenv("DISPLAY", ":0", 1);
+#else
+			putenv("DISPLAY=:0");
+#endif
+		} else {
+#ifdef HAVE_UNSETENV
+			unsetenv("DISPLAY");
+#else
+			putenv("DISPLAY");
+#endif
+		}
+	} else { /* restore DISPLAY */
+		if (display) {
+#ifdef HAVE_SETENV
+			setenv("DISPLAY", display, 1);
+#else
+			{
+				static unsigned char DISPLAY[1024] = { 'D','I','S','P','L','A','Y','=' };
+
+				strncpy(DISPLAY + 8, display, 1023 - 8);
+				putenv(DISPLAY);
+			}
+#endif
+			mem_free(display);
+		} else {
+#ifdef HAVE_UNSETENV
+			unsetenv("DISPLAY");
+#else
+			putenv("DISPLAY");
+#endif
+		}
+	}
+}
+#endif
+
 static struct mime_handler *
-get_mime_handler_mailcap(unsigned char *type, int options)
+get_mime_handler_mailcap(unsigned char *type, int xwin)
 {
 	struct mailcap_entry *entry;
 	struct mime_handler *handler;
@@ -658,7 +707,14 @@ get_mime_handler_mailcap(unsigned char *type, int options)
 	    || (!mailcap_map && !init_mailcap_map()))
 		return NULL;
 
+#if defined(HAVE_SETENV) || defined(HAVE_PUTENV)
+	set_display(xwin, 0);
+#endif
 	entry = get_mailcap_entry(type);
+
+#if defined(HAVE_SETENV) || defined(HAVE_PUTENV)
+	set_display(xwin, 1);
+#endif
 	if (!entry) return NULL;
 
 	program = format_command(entry->command, type, entry->copiousoutput);