[gdk-pixbuf] png: Return error for truncated PNG files

[Bastien Nocera <hadess src gnome org>]

commit 447bd32650af6be56993c474d3ad64d58cc0a7d2
Author: Felix Riemann <friemann gnome org>
Date:   Wed Aug 27 10:59:00 2008 +0000

    png: Return error for truncated PNG files
    
    When a PNG image couldn't be loaded at the end of a progressive
    load operation, throw an error.
    
    The error string is already translated as part of the BMP and
    PNM loaders.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=524216

 gdk-pixbuf/io-png.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/gdk-pixbuf/io-png.c b/gdk-pixbuf/io-png.c
index 83e46ff..ae0fafe 100644
--- a/gdk-pixbuf/io-png.c
+++ b/gdk-pixbuf/io-png.c
@@ -496,6 +496,7 @@ static gboolean
 gdk_pixbuf__png_image_stop_load (gpointer context, GError **error)
 {
         LoadContext* lc = context;
+        gboolean retval = TRUE;
 
         g_return_val_if_fail(lc != NULL, TRUE);
 
@@ -505,11 +506,19 @@ gdk_pixbuf__png_image_stop_load (gpointer context, GError **error)
         
         if (lc->pixbuf)
                 g_object_unref (lc->pixbuf);
+        else {
+                if (error && *error == NULL) {
+                        g_set_error_literal (error, GDK_PIXBUF_ERROR,
+                                             GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
+                                             _("Premature end-of-file encountered"));
+                }
+                retval = FALSE;
+       }
         
         png_destroy_read_struct(&lc->png_read_ptr, &lc->png_info_ptr, NULL);
         g_free(lc);
 
-        return TRUE;
+        return retval;
 }
 
 static gboolean