Index: gdk-pixbuf-io.c
===================================================================
RCS file: /cvs/gnome/gtk+/gdk-pixbuf/gdk-pixbuf-io.c,v
retrieving revision 1.105.2.3
diff -u -p -r1.105.2.3 gdk-pixbuf-io.c
--- gdk-pixbuf-io.c	30 Mar 2005 19:42:30 -0000	1.105.2.3
+++ gdk-pixbuf-io.c	1 Jul 2005 16:57:45 -0000
@@ -939,18 +939,35 @@ size_prepared_cb (GdkPixbufLoader *loade
 
 	g_return_if_fail (width > 0 && height > 0);
 
-	if(info->preserve_aspect_ratio) {
-		if ((double)height * (double)info->width >
-		    (double)width * (double)info->height) {
-			width = 0.5 + (double)width * (double)info->height / (double)height;
-			height = info->height;
-		} else {
-			height = 0.5 + (double)height * (double)info->width / (double)width;
-			width = info->width;
-		}
+	if (info->preserve_aspect_ratio) {
+		if (info->width != -1 && info->height != -1) {
+                        double width_ratio;
+                        double height_ratio;
+
+                        width_ratio = (double)info->width / (double)width;
+                        height_ratio = (double)info->height / (double)height;
+
+                        if (width_ratio > height_ratio) {
+                                width = 0.5 + (double)width * height_ratio;
+                                height = info->height;
+                        } else {
+                                height = 0.5 + (double)height * width_ratio;
+                                width = info->width;
+                        }
+                } else if (info->width != -1 || info->height != -1) {
+                        double ratio;
+
+                        if (info->width == -1)
+                                ratio = (double)info->height / (double)height;
+                        else
+                                ratio = (double)info->width / (double)width;
+
+                        width = 0.5 + (double)width * ratio;
+                        height = 0.5 + (double)height * ratio;
+                }
 	} else {
-		width = info->width;
-		height = info->height;
+		width = info->width != -1 ? info->width : width;
+		height = info->height != -1 ? info->height : height;
 	}
 	
 	gdk_pixbuf_loader_set_size (loader, width, height);
@@ -959,8 +976,8 @@ size_prepared_cb (GdkPixbufLoader *loade
 /**
  * gdk_pixbuf_new_from_file_at_size:
  * @filename: Name of file to load, in the GLib file name encoding
- * @width: The width the image should have
- * @height: The height the image should have
+ * @width: The width the image should have or -1 to preserve the width
+ * @height: The height the image should have or -1 to preserve the height
  * @error: Return location for an error
  *
  * Creates a new pixbuf by loading an image from a file.  The file format is
@@ -1018,8 +1035,8 @@ gdk_pixbuf_new_from_file_at_size (const 
 /**
  * gdk_pixbuf_new_from_file_at_scale:
  * @filename: Name of file to load, in the GLib file name encoding
- * @width: The width the image should have
- * @height: The height the image should have
+ * @width: The width the image should have or -1 to preserve the width
+ * @height: The height the image should have or -1 to preserve the height
  * @preserve_aspect_ratio: %TRUE to preserve the image's aspect ratio
  * @error: Return location for an error
  *
@@ -1057,7 +1074,8 @@ gdk_pixbuf_new_from_file_at_scale (const
 	} info;
 
 	g_return_val_if_fail (filename != NULL, NULL);
-        g_return_val_if_fail (width > 0 && height > 0, NULL);
+        g_return_val_if_fail (width > 0 || width == -1, NULL);
+        g_return_val_if_fail (height > 0 || height == -1, NULL);
 
 	f = g_fopen (filename, "rb");
 	if (!f) {