[gthumb] check whether the image is null before using it

[Paolo Bacchilega <paobac src gnome org>]

commit c4da6472c0e1b31c62822ef6cc4e38f85e9fed5d
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Wed Feb 18 12:58:21 2015 +0100

    check whether the image is null before using it

 gthumb/gth-image.c |   48 ++++++++++++++++++++++++++----------------------
 1 files changed, 26 insertions(+), 22 deletions(-)
---
diff --git a/gthumb/gth-image.c b/gthumb/gth-image.c
index 94d2fe0..f9a166f 100644
--- a/gthumb/gth-image.c
+++ b/gthumb/gth-image.c
@@ -538,11 +538,6 @@ gth_image_apply_icc_profile (GthImage      *image,
        GthICCProfile    image_profile;
        cmsHTRANSFORM    hTransform;
        cairo_surface_t *surface;
-       unsigned char   *surface_row;
-       int              width;
-       int              height;
-       int              row_stride;
-       int              row;
 
        g_return_if_fail (image != NULL);
 
@@ -556,30 +551,39 @@ gth_image_apply_icc_profile (GthImage      *image,
        if (image->priv->format != GTH_IMAGE_FORMAT_CAIRO_SURFACE)
                return;
 
+       surface = gth_image_get_cairo_surface (image);
+       if (surface == NULL)
+               return;
+
        hTransform = cmsCreateTransform ((cmsHPROFILE) image_profile,
                                         _LCMS2_CAIRO_FORMAT,
                                         (cmsHPROFILE) out_profile,
                                         _LCMS2_CAIRO_FORMAT,
                                         INTENT_PERCEPTUAL, 0);
-       if (hTransform == NULL)
-               return;
 
-       surface = gth_image_get_cairo_surface (image);
-       surface_row = _cairo_image_surface_flush_and_get_data (surface);
-       width = cairo_image_surface_get_width (surface);
-       height = cairo_image_surface_get_height (surface);
-       row_stride = cairo_image_surface_get_stride (surface);
-
-       for (row = 0; row < height; row++) {
-               if (g_cancellable_is_cancelled (cancellable))
-                       break;
-               cmsDoTransform (hTransform, surface_row, surface_row, width);
-               surface_row += row_stride;
-       }
-       cairo_surface_mark_dirty (surface);
+       if (hTransform != NULL) {
+               unsigned char   *surface_row;
+               int              width;
+               int              height;
+               int              row_stride;
+               int              row;
+
+               surface_row = _cairo_image_surface_flush_and_get_data (surface);
+               width = cairo_image_surface_get_width (surface);
+               height = cairo_image_surface_get_height (surface);
+               row_stride = cairo_image_surface_get_stride (surface);
+
+               for (row = 0; row < height; row++) {
+                       if (g_cancellable_is_cancelled (cancellable))
+                               break;
+                       cmsDoTransform (hTransform, surface_row, surface_row, width);
+                       surface_row += row_stride;
+               }
+               cairo_surface_mark_dirty (surface);
 
-       cairo_surface_destroy (surface);
-       cmsDeleteTransform (hTransform);
+               cairo_surface_destroy (surface);
+               cmsDeleteTransform (hTransform);
+       }
 
 #endif
 }