[gdk-pixbuf] tests: Add small tool to save a reference image

[Bastien Nocera <hadess src gnome org>]

commit e96cbf246b530d508106fdc528e24ca384e6cff0
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Dec 28 16:11:22 2016 +0100

    tests: Add small tool to save a reference image
    
    This makes it easier to create a reference image after a bug has been
    fixed. Reverting the fix is enough to show that the reftest fails
    without it.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696331

 tests/Makefile.am       |    1 +
 tests/pixbuf-save-ref.c |  102 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 0 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ca91ed1..71e39bc 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -20,6 +20,7 @@ noinst_PROGRAMS +=                    \
        pixbuf-read                     \
        pixbuf-random                   \
        pixbuf-lowmem                   \
+       pixbuf-save-ref                 \
        $(NULL)
 
 test_programs =                        \
diff --git a/tests/pixbuf-save-ref.c b/tests/pixbuf-save-ref.c
new file mode 100644
index 0000000..e805c13
--- /dev/null
+++ b/tests/pixbuf-save-ref.c
@@ -0,0 +1,102 @@
+/* -*- Mode: C; c-basic-offset: 2; -*- */
+/* GdkPixbuf library - test loaders
+ *
+ * Copyright (C) 2001 S�ren Sandmann (sandmann daimi au dk)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+#include "gdk-pixbuf/gdk-pixbuf.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+static gboolean
+load_and_save (const char *filename, GError **error)
+{
+  GdkPixbuf *pixbuf;
+  GdkPixbufLoader *loader;
+  guchar *contents;
+  char *new_filename = NULL;
+  gsize size;
+  gboolean ret = TRUE;
+
+  if (!g_file_get_contents (filename, (char **) &contents, &size, error))
+    return FALSE;
+
+  loader = gdk_pixbuf_loader_new ();
+  if (!gdk_pixbuf_loader_write (loader, contents, size, error))
+    {
+      ret = FALSE;
+      goto out;
+    }
+
+  pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
+  g_assert (pixbuf);
+  g_object_ref (pixbuf);
+
+  if (!gdk_pixbuf_loader_close (loader, error))
+    {
+      ret = FALSE;
+      goto out;
+    }
+  g_object_unref (loader);
+
+  new_filename = g_strdup_printf ("%s.ref.png", filename);
+  ret = gdk_pixbuf_save (pixbuf, new_filename, "png", error, NULL);
+
+out:
+  g_free (contents);
+  g_free (new_filename);
+  g_object_unref (pixbuf);
+
+  return ret;
+}
+
+static void
+usage (void)
+{
+  g_print ("usage: pixbuf-save-ref <files>\n");
+  exit (EXIT_FAILURE);
+}
+
+int
+main (int argc, char **argv)
+{
+  int i;
+
+  g_log_set_always_fatal (G_LOG_LEVEL_WARNING | G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL);
+
+  if (argc == 1)
+    usage();
+
+  for (i = 1; i < argc; ++i)
+    {
+      GError *err = NULL;
+
+      g_print ("%s\t\t", argv[i]);
+      fflush (stdout);
+      if (!load_and_save (argv[i], &err))
+        {
+          fprintf (stderr, "%s: error: %s\n", argv[i], err->message);
+          g_clear_error (&err);
+        }
+      else
+        {
+          g_print ("success\n");
+        }
+    }
+
+  return 0;
+}