Add all icon directories into icon theme search path in maintainer mode

When building into a custom prefix, the icons in PREFIX/share/icons/ may
not be found in some cases, thus, when building also with
the ENABLE_MAINTAINER_MODE, add also that directory into the gtk+
icon theme search path.

config.h.in

@@ -27,6 +27,9 @@
 /* Package name for gettext */
 #define GETTEXT_PACKAGE "@GETTEXT_PACKAGE@"
 
+/* Defined, when configured with ENABLE_MAINTAINER_MODE */
+#cmakedefine ENABLE_MAINTAINER_MODE 1
+
 /* Command to kill processes by name */
 #cmakedefine KILL_PROCESS_COMMAND "@KILL_PROCESS_COMMAND@"
 

src/shell/CMakeLists.txt

@@ -130,6 +130,7 @@ target_compile_definitions(evolution PRIVATE
 	-DEVOLUTION_GALVIEWSDIR=\"${viewsdir}\"
 	-DEVOLUTION_HELPDIR=\"${evolutionhelpdir}\"
 	-DEVOLUTION_ICONDIR=\"${icondir}\"
+	-DEVOLUTION_ICONDIR_IN_PREFIX=\"${SHARE_INSTALL_PREFIX}/icons\"
 	-DEVOLUTION_MODULEDIR=\"${moduledir}\"
 	-DEVOLUTION_RULEDIR=\"${privdatadir}\"
 	-DEVOLUTION_TOOLSDIR=\"${privlibexecdir}\"

src/shell/main.c

@@ -448,6 +448,9 @@ main (gint argc,
 {
 	EShell *shell;
 	GSettings *settings;
+#ifdef ENABLE_MAINTAINER_MODE
+	GtkIconTheme *icon_theme;
+#endif
 #ifdef DEVELOPMENT
 	gboolean skip_warning_dialog;
 #endif
@@ -590,6 +593,11 @@ main (gint argc,
 	if (setup_only)
 		exit (0);
 
+#ifdef ENABLE_MAINTAINER_MODE
+	icon_theme = gtk_icon_theme_get_default ();
+	gtk_icon_theme_prepend_search_path (icon_theme, EVOLUTION_ICONDIR_IN_PREFIX);
+#endif
+
 	categories_icon_theme_hack ();
 	gtk_accel_map_load (e_get_accels_filename ());