return a negative error code instead of exiting on parse error

Original commit message from CVS:
return a negative error code instead of exiting on parse error

gst/gstparse.c

@@ -247,22 +247,22 @@ gst_parse_launch_cmdline(int argc,char *argv[],GstBin *parent,gst_parse_priv *pr
       // rename previous element to next arg.
       if (arg[1] != '\0') {
         fprintf(stderr,"error, unexpected junk after [\n");
-	exit(-1);
+        return GST_PARSE_ERROR_SYNTAX;
       }
       i++;
       if (i < argc) {
         gst_element_set_name(previous, argv[i]);
       } else {
         fprintf(stderr,"error, expected element name, found end of arguments\n");
-	exit(-1);
+        return GST_PARSE_ERROR_SYNTAX;
       }
       i++;
       if (i >= argc) {
         fprintf(stderr,"error, expected ], found end of arguments\n");
-	exit(-1);
+        return GST_PARSE_ERROR_SYNTAX;
       } else if (strcmp(argv[i], "]") != 0) {
         fprintf(stderr,"error, expected ], found '%s'\n", argv[i]);
-	exit(-1);
+        return GST_PARSE_ERROR_SYNTAX;
       }
     } else {
       DEBUG("have element or bin/thread\n");
@@ -273,7 +273,7 @@ gst_parse_launch_cmdline(int argc,char *argv[],GstBin *parent,gst_parse_priv *pr
           element = gst_bin_new(g_strdup_printf("bin%d",priv->bincount++));
           if (!element) {
             fprintf(stderr,"Couldn't create a bin!\n");
-//            exit(-1);
+            return GST_PARSE_ERROR_CREATING_ELEMENT;
           }
           GST_DEBUG(0,"CREATED bin %s\n",GST_ELEMENT_NAME(element));
         } else if (arg[0] == '{') {
@@ -281,7 +281,7 @@ gst_parse_launch_cmdline(int argc,char *argv[],GstBin *parent,gst_parse_priv *pr
           element = gst_thread_new(g_strdup_printf("thread%d",priv->threadcount++));
           if (!element) {
             fprintf(stderr,"Couldn't create a thread!\n");
-//            exit(-1);
+            return GST_PARSE_ERROR_CREATING_ELEMENT;
           }
           GST_DEBUG(0,"CREATED thread %s\n",GST_ELEMENT_NAME(element));
 	} else {
@@ -290,7 +290,10 @@ gst_parse_launch_cmdline(int argc,char *argv[],GstBin *parent,gst_parse_priv *pr
 	  continue;
 	}
 
-        i += gst_parse_launch_cmdline(argc - i, argv + i + 1, GST_BIN (element), priv);
+        j = gst_parse_launch_cmdline(argc - i, argv + i + 1, GST_BIN (element), priv);
+        //check for parse error
+        if (j < 0) return j;
+        i += j;
 
       } else {
         // we have an element
@@ -304,7 +307,7 @@ gst_parse_launch_cmdline(int argc,char *argv[],GstBin *parent,gst_parse_priv *pr
 #else
           fprintf(stderr,"Couldn't create a '%s', no such element or need to load pluginn?\n",arg);
 #endif
-          exit(-1);
+          return GST_PARSE_ERROR_NOSUCH_ELEMENT;
         }
         GST_DEBUG(0,"CREATED element %s\n",GST_ELEMENT_NAME(element));
       }

gst/gstparse.h

@@ -31,6 +31,12 @@ extern "C" {
 
 #ifndef GST_DISABLE_PARSE
 
+typedef enum {
+  GST_PARSE_ERROR_SYNTAX = -1, 
+  GST_PARSE_ERROR_CREATING_ELEMENT = -2,
+  GST_PARSE_ERROR_NOSUCH_ELEMENT = -3,
+} GstParseErrors;
+  
 gint	gst_parse_launch	(const gchar *cmdline, GstBin *parent);
 
 #else // GST_DISABLE_PARSE

tools/gstreamer-guilaunch.c

@@ -516,6 +516,7 @@ parse_callback( GtkWidget *widget,
 	GtkWidget *tree_item = (GtkWidget*)gtk_object_get_data(GTK_OBJECT(widget), "tree_item");
 	gchar *last_pipe = (gchar*)gtk_object_get_data(GTK_OBJECT(widget), "last_pipe");
 	gchar *try_pipe = gtk_entry_get_text(GTK_ENTRY(GTK_COMBO(pipe_combo)->entry));
+	gint parse_result;
 		
 	if (pipeline){
 		g_print("unreffing\n");
@@ -524,7 +525,25 @@ parse_callback( GtkWidget *widget,
 	g_print ("trying pipeline: %s\n", try_pipe);
 	
 	pipeline = gst_pipeline_new ("launch");
-	gst_parse_launch (try_pipe, GST_BIN (pipeline));
+	parse_result = gst_parse_launch (try_pipe, GST_BIN (pipeline));
+	if (parse_result < 0){
+		switch(parse_result){
+			case GST_PARSE_ERROR_SYNTAX:
+				gtk_label_set_text(GTK_LABEL(status), "error parsing syntax of pipeline");
+				break;
+			case GST_PARSE_ERROR_CREATING_ELEMENT:
+				gtk_label_set_text(GTK_LABEL(status), "error creating a core element");
+				break;
+			case GST_PARSE_ERROR_NOSUCH_ELEMENT:
+				gtk_label_set_text(GTK_LABEL(status), "error finding an element which was requested");
+				break;
+			default:
+				gtk_label_set_text(GTK_LABEL(status), "unknown error parsing pipeline");
+				break;
+		}
+		gst_object_unref (GST_OBJECT (pipeline));
+		return;
+	}			
 	gtk_widget_set_sensitive(GTK_WIDGET(start_but), TRUE);
 
 	build_tree(tree_item, GST_BIN(pipeline));

tools/gstreamer-launch.c

@@ -152,7 +152,10 @@ main(int argc, char *argv[])
     exit(1);
   }
 
-  gst_parse_launch (cmdline, GST_BIN (pipeline));
+  if (gst_parse_launch (cmdline, GST_BIN (pipeline)) < 0){
+    fprintf(stderr,"ERROR: pipeline description could not be parsed\n");
+    exit(1);
+  }
 
 #ifndef GST_DISABLE_LOADSAVE
   if (save_pipeline) {