[gdk-pixbuf] TIFF: assert and assume that the module callbacks are non-NULL

[Emmanuele Bassi <ebassi src gnome org>]

commit 0d89b4ea0a636df4a1be7cbc40fa947e86488ff3
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Nov 28 19:22:08 2017 -0600

    TIFF: assert and assume that the module callbacks are non-NULL

 gdk-pixbuf/io-tiff.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/gdk-pixbuf/io-tiff.c b/gdk-pixbuf/io-tiff.c
index 8d9780583..79c23d4cc 100644
--- a/gdk-pixbuf/io-tiff.c
+++ b/gdk-pixbuf/io-tiff.c
@@ -153,7 +153,7 @@ tiff_image_parse (TIFF *tiff, TiffContext *context, GError **error)
 
         bytes = height * rowstride;
 
-       if (context && context->size_func) {
+       if (context) {
                 gint w = width;
                 gint h = height;
                (* context->size_func) (&w, &h, context->user_data);
@@ -276,7 +276,7 @@ tiff_image_parse (TIFF *tiff, TiffContext *context, GError **error)
                 }
         }
 
-       if (context && context->prepare_func)
+       if (context)
                (* context->prepare_func) (pixbuf, NULL, context->user_data);
 
        if (!TIFFReadRGBAImageOriented (tiff, width, height, (uint32 *)pixels, ORIENTATION_TOPLEFT, 1)) {
@@ -316,7 +316,7 @@ tiff_image_parse (TIFF *tiff, TiffContext *context, GError **error)
         }
 #endif
 
-       if (context && context->update_func)
+       if (context)
                (* context->update_func) (pixbuf, 0, 0, width, height, context->user_data);
 
         return pixbuf;
@@ -398,6 +398,10 @@ gdk_pixbuf__tiff_image_begin_load (GdkPixbufModuleSizeFunc size_func,
 {
        TiffContext *context;
         
+        g_assert (size_func != NULL);
+        g_assert (prepare_func != NULL);
+        g_assert (update_func != NULL);
+
        context = g_new0 (TiffContext, 1);
        context->size_func = size_func;
        context->prepare_func = prepare_func;