[seed] add backtrace stack to the exception string

[Alan Knowles <alank src gnome org>]

commit 9f1c31e475e5b782edca239023eaf0d64ddc37fc
Author: Alan Knowles <alan roojs com>
Date:   Fri Aug 10 18:55:52 2012 +0800

    add backtrace stack to the exception string

 libseed/seed-exceptions.c |   27 +++++++++++++++++++++++++--
 libseed/seed-exceptions.h |    1 +
 2 files changed, 26 insertions(+), 2 deletions(-)
---
diff --git a/libseed/seed-exceptions.c b/libseed/seed-exceptions.c
index 2025e77..abaa210 100644
--- a/libseed/seed-exceptions.c
+++ b/libseed/seed-exceptions.c
@@ -208,6 +208,28 @@ seed_exception_get_file (JSContextRef ctx, JSValueRef e)
   line = seed_object_get_property (ctx, (JSObjectRef) e, "sourceURL");
   return seed_value_to_string (ctx, line, 0);
 }
+/**
+ * seed_exception_get_stack:
+ * @ctx: A #SeedContext.
+ * @exception: A reference to a #SeedException.
+ *
+ * Retrieves the backtrace stack (if available..
+ *
+ * Return value: A #gchar* representing the name of the file from which
+ *               @exception was thrown.
+ *
+ */
+gchar *
+seed_exception_get_stack (JSContextRef ctx, JSValueRef e)
+{
+  JSValueRef stack ;
+  g_assert ((e));
+  if (!JSValueIsObject (ctx, e))
+    return 0;
+  stack = seed_object_get_property (ctx, (JSObjectRef) e, "stack");
+  return seed_value_to_string (ctx, stack , 0);
+}
+
 
 /**
  * seed_exception_to_string:
@@ -226,14 +248,15 @@ gchar *
 seed_exception_to_string (JSContextRef ctx, JSValueRef e)
 {
   guint line;
-  gchar *mes, *name, *file, *ret;
+  gchar *mes, *name, *file, *ret, *stack;
 
   line = seed_exception_get_line (ctx, e);
   mes = seed_exception_get_message (ctx, e);
   file = seed_exception_get_file (ctx, e);
   name = seed_exception_get_name (ctx, e);
+  stack = seed_exception_get_stack (ctx, e);
 
-  ret = g_strdup_printf ("Line %d in %s: %s %s", line, file, name, mes);
+  ret = g_strdup_printf ("Line %d in %s: %s %s\n\nStack:\n%s", line, file, name, mes, stack);
 
   g_free (mes);
   g_free (file);
diff --git a/libseed/seed-exceptions.h b/libseed/seed-exceptions.h
index cefdf70..cc1a261 100644
--- a/libseed/seed-exceptions.h
+++ b/libseed/seed-exceptions.h
@@ -35,6 +35,7 @@ G_GNUC_PRINTF (4, 5);
      gchar *seed_exception_get_message (JSContextRef ctx, JSValueRef e);
      guint seed_exception_get_line (JSContextRef ctx, JSValueRef e);
      gchar *seed_exception_get_file (JSContextRef ctx, JSValueRef e);
+     gchar *seed_exception_get_stack (JSContextRef ctx, JSValueRef e);
      gchar *seed_exception_to_string (JSContextRef ctx, JSValueRef e);
 
 #endif