Add -rasi-validate option.

Issue: #1260

doc/rofi.1

@@ -215,6 +215,12 @@ Dump the current active theme, in rasi format, to stdout and exit.
 Dump the current active configuration, in Xresources format, to stdout.
 This does not validate all passed values (for example, colors).
 
+.PP
+\fB\fC\-rasi\-validate\fR \fIfilename\fP
+
+.PP
+Try to parse the file and 0 when succesful.
+
 .PP
 \fB\fC\-threads\fR \fInum\fP
 

doc/rofi.1.markdown

@@ -128,6 +128,10 @@ Dump the current active theme, in rasi format, to stdout and exit.
 Dump the current active configuration, in Xresources format, to stdout.
 This does not validate all passed values (for example, colors).
 
+`-rasi-validate` *filename*
+
+Try to parse the file and 0 when succesful.
+
 `-threads` *num*
 
 Specify the number of threads **rofi** should use:

include/theme.h

@@ -387,4 +387,12 @@ void rofi_theme_parse_merge_widgets ( ThemeWidget *parent, ThemeWidget *child );
  */
 ThemeMediaType rofi_theme_parse_media_type ( const char *type );
 RofiDistance rofi_theme_property_copy_distance  ( RofiDistance const distance );
+
+/**
+ * @param filename The file to validate.
+ *
+ * @returns the program exit code.
+ */
+int rofi_theme_rasi_validate ( const char *filename );
+
 #endif

source/rofi.c

@@ -796,6 +796,19 @@ int main ( int argc, char *argv[] )
         return EXIT_SUCCESS;
     }
 
+    if ( find_arg ( "-rasi-validate" ) >= 0 ) {
+        char *str = NULL;
+        find_arg_str ( "-rasi-validate", &str );
+        if ( str != NULL ) {
+            int retv = rofi_theme_rasi_validate ( str );
+            cleanup ();
+            return retv;
+        }
+        fprintf ( stderr, "Usage: %s -rasi-validate my-theme.rasi", argv[0] );
+        return EXIT_FAILURE;
+    }
+
+
     {
         const char *ro_pid = g_getenv ( "ROFI_OUTSIDE" );
         if ( ro_pid != NULL ) {
@@ -1158,3 +1171,21 @@ int main ( int argc, char *argv[] )
     g_free ( windowid );
     return return_code;
 }
+
+
+/** List of error messages.*/
+extern GList *list_of_error_msgs;
+int rofi_theme_rasi_validate ( const char *filename )
+{
+    rofi_theme_parse_file ( filename );
+    if ( list_of_error_msgs == NULL ) {
+        return EXIT_SUCCESS;
+    }
+
+    for ( GList *iter = g_list_first ( list_of_error_msgs );
+            iter != NULL; iter = g_list_next ( iter ) ) {
+        fputs ( ((GString*)iter->data)->str, stderr );
+    }
+
+    return EXIT_FAILURE;
+}