[gdk-pixbuf] tests: Add test for bug 581484

[Bastien Nocera <hadess src gnome org>]

commit 6ce3b60e7cb7f48d6990644d0d42b1b0a923569e
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Dec 29 16:08:42 2016 +0100

    tests: Add test for bug 581484
    
    Adapted from Andrey Tsyvarev's original test program.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=581484

 tests/Makefile.am           |    7 ++
 tests/pixbuf-area-updated.c |  203 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 210 insertions(+), 0 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 71e39bc..dcec2df 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -42,6 +42,7 @@ test_programs =                       \
        pixbuf-save                     \
        pixbuf-readonly-to-mutable      \
        pixbuf-composite                \
+       pixbuf-area-updated             \
        $(NULL)
 
 dist_installed_test_data =             \
@@ -71,6 +72,12 @@ dist_installed_test_data =           \
        $(wildcard $(srcdir)/test-images/reftests/tga/*) \
        $(NULL)
 
+pixbuf_area_updated_SOURCES =          \
+       pixbuf-area-updated.c           \
+       test-common.c                   \
+       test-common.h                   \
+       $(NULL)
+
 pixbuf_randomly_modified_SOURCES =     \
        pixbuf-randomly-modified.c      \
        test-common.c                   \
diff --git a/tests/pixbuf-area-updated.c b/tests/pixbuf-area-updated.c
new file mode 100644
index 0000000..9c4f0e8
--- /dev/null
+++ b/tests/pixbuf-area-updated.c
@@ -0,0 +1,203 @@
+/* -*- Mode: C; c-basic-offset: 2; -*- */
+/* GdkPixbuf library - test loaders
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ *
+ * 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/>.
+ *
+ * Author: Andrey Tsyvarev
+ *         Bastien Nocera
+ */
+
+#include <stdio.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+/* Auxiliary function, returns numeric representation of pixel.
+ * For RGB format it is rrggbb(in hex), for RGBA - rrggbbaa. */
+static guint32
+get_pixel (GdkPixbuf *pixbuf, int x, int y)
+{
+    guchar *colors;
+    guint32 pixel;
+
+    colors = ((guchar*)gdk_pixbuf_get_pixels(pixbuf)
+             + gdk_pixbuf_get_n_channels(pixbuf) * x
+             + gdk_pixbuf_get_rowstride(pixbuf) * y);
+    pixel = (colors[0] << 16) | (colors[1] << 8) | colors[2];
+
+    if (gdk_pixbuf_get_n_channels (pixbuf) == 4)
+        pixel = (pixel << 8) | colors[3];
+
+    return pixel;
+}
+/* Verify whether all pixels outside the updated area
+ * have the same values in pixbuf_old and pixbuf_new. */
+static gboolean
+pixbuf_not_changed_outside_area (GdkPixbuf *pixbuf_new,
+                                GdkPixbuf *pixbuf_old,
+                                int        x,
+                                int        y,
+                                int        width,
+                                int        height)
+{
+    int pixbuf_width, pixbuf_height;
+    int x_curr, y_curr;
+
+    pixbuf_width = gdk_pixbuf_get_width (pixbuf_new);
+    pixbuf_height = gdk_pixbuf_get_height (pixbuf_new);
+
+    for (x_curr = 0; x_curr < pixbuf_width; x_curr++) {
+        for (y_curr = 0; y_curr < pixbuf_height; y_curr++) {
+            if ((x_curr >= x)
+                && (x_curr < x + width)
+                && (y_curr >= y)
+                && (y_curr < y + height)) {
+                continue; /* inside area - don't compare pixels. */
+            }
+            if (get_pixel (pixbuf_new, x_curr, y_curr) != get_pixel (pixbuf_old, x_curr, y_curr)) {
+                printf("Pixel at (%d, %d) changed from %x to %x,\n",
+                       x_curr, y_curr,
+                       get_pixel (pixbuf_old, x_curr, y_curr),
+                       get_pixel (pixbuf_new, x_curr, y_curr));
+                printf("But it is outside of area with ");
+                printf("x=%d, y=%d, width=%d, height=%d\n",
+                       x, y, width, height);
+
+#if 0
+                gdk_pixbuf_save (pixbuf_old, "old.png", "png", NULL, NULL);
+                gdk_pixbuf_save (pixbuf_new, "new.png", "png", NULL, NULL);
+#endif
+
+                g_assert_not_reached ();
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+static void
+callback_area_updated (GdkPixbufLoader *loader,
+                       int              x,
+                       int              y,
+                       int              width,
+                       int              height,
+                       GdkPixbuf       *pixbuf_old)
+{
+    GdkPixbuf *pixbuf_new;
+
+    pixbuf_new = gdk_pixbuf_loader_get_pixbuf (loader);
+
+    pixbuf_not_changed_outside_area (pixbuf_new, pixbuf_old, x, y, width, height);
+    /* update copy of pixbuf */
+    gdk_pixbuf_copy_area (pixbuf_new, x, y, width, height, pixbuf_old, x, y);
+}
+
+/* free copy of pixbuf used in area-updated callback. */
+static void
+callback_closed (GdkPixbufLoader *loader,
+                 GdkPixbuf       *pixbuf_copy)
+{
+    g_object_unref (pixbuf_copy);
+}
+
+/* prepare copy of pixbuf and connect other callbacks */
+static void
+callback_area_prepared (GdkPixbufLoader *loader)
+{
+    GdkPixbuf *pixbuf_copy;
+
+    pixbuf_copy = gdk_pixbuf_copy (gdk_pixbuf_loader_get_pixbuf (loader));
+    /* connect callbacks for another signals for not use pointer to pointer in them. */
+    g_signal_connect (loader, "area-updated",
+                      (GCallback) callback_area_updated, (gpointer) pixbuf_copy);
+    g_signal_connect (loader, "closed",
+                      (GCallback) callback_closed, (gpointer) pixbuf_copy);
+}
+
+/* Read count_bytes from the channel and write them to the loader.
+ * Returns number of bytes written.
+ * count_bytes = G_MAXSIZE means read as many bytes as possible. */
+static gsize
+loader_write_from_channel (GdkPixbufLoader *loader,
+                           GIOChannel      *channel,
+                           gsize            count_bytes)
+{
+    guchar* buffer;
+    gsize bytes_read;
+    GIOStatus read_status;
+
+    if(count_bytes < G_MAXSIZE) {
+        /* read no more than 'count_bytes' bytes */
+        buffer = g_malloc(count_bytes);
+        read_status = g_io_channel_read_chars (channel, (gchar*) buffer, count_bytes, &bytes_read, NULL);
+    } else {
+        /*read up to end */
+        read_status = g_io_channel_read_to_end (channel, (gchar**) &buffer, &bytes_read, NULL);
+    }
+
+    if ((read_status != G_IO_STATUS_NORMAL) && (read_status != G_IO_STATUS_EOF))
+        g_assert_not_reached ();
+
+    if (!gdk_pixbuf_loader_write(loader, buffer, bytes_read, NULL))
+        g_assert_not_reached ();
+
+    g_free (buffer);
+    return bytes_read;
+}
+
+static void
+test_area_updated_ico (gconstpointer data)
+{
+    const char *filename;
+    GIOChannel *channel;
+    GdkPixbufLoader *loader;
+
+    filename = g_test_get_filename (G_TEST_DIST, data, NULL);
+
+    /* create channel */
+    channel = g_io_channel_new_file(filename, "r", NULL);
+    g_assert_nonnull (channel);
+    g_io_channel_set_encoding (channel, NULL, NULL);
+    /* create loader */
+    loader = gdk_pixbuf_loader_new ();
+    g_assert_nonnull (loader);
+
+    g_signal_connect(loader, "area-prepared",
+                    (GCallback) callback_area_prepared, NULL);
+    /* callbacks for "area-updated" and "closed" signals will be connected
+     * in callback_area_prepared() */
+
+    /* read image byte by byte */
+    while (loader_write_from_channel(loader, channel, 1) == 1);
+    /* or read full image at once */
+#if 0
+    loader_write_from_channel(loader, channel, G_MAXSIZE);
+#endif
+
+    /* free resources */
+    g_io_channel_unref (channel);
+
+    gdk_pixbuf_loader_close (loader, NULL);
+    g_object_unref (loader);
+}
+
+int main(int argc, char **argv)
+{
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add_data_func ("/pixbuf/area-updated/ico", (gconstpointer) "test-images/reftests/squares.ico", 
test_area_updated_ico);
+
+  return g_test_run ();
+}