[cairo] [PATCH]: gl: Return surface in error when creating oversized texture surfaces

[Martin Robinson]

>From 33d7b642d615d0d5d9b2792b9510a501a6b8a4f6 Mon Sep 17 00:00:00 2001
From: Martin Robinson <mrobinson at igalia.com>
Date: Mon, 29 Jul 2013 11:14:34 -0700
Subject: [PATCH] gl: Return surface in error when creating oversized texture
 surfaces

When creating a texture surface that is larger than the maximum
framebuffer or texture dimensions of the context, return a surface in
error. Previously the code failed an assertion, but this prevents an
application from easily detecting when to fall back.
---
 src/cairo-gl-surface.c      | 14 +++++++-
 test/Makefile.sources       |  1 +
 test/gl-oversized-surface.c | 86 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 test/gl-oversized-surface.c

diff --git a/src/cairo-gl-surface.c b/src/cairo-gl-surface.c
index f6b7928..16f1c4f 100644
--- a/src/cairo-gl-surface.c
+++ b/src/cairo-gl-surface.c
@@ -395,6 +395,16 @@ _cairo_gl_surface_init (cairo_device_t *device,
     _cairo_gl_surface_embedded_operand_init (surface);
 }
 
+static cairo_bool_t valid_size (cairo_gl_context_t *ctx,
+				int width, int height)
+{
+    return width >= 0 && width <= ctx->max_framebuffer_size &&
+	   height >= 0 && height <= ctx->max_framebuffer_size &&
+	   width <= ctx->max_texture_size &&
+	   height <= ctx->max_texture_size;
+}
+
+
 static cairo_surface_t *
 _cairo_gl_surface_create_scratch_for_texture (cairo_gl_context_t   *ctx,
 					      cairo_content_t	    content,
@@ -404,7 +414,9 @@ _cairo_gl_surface_create_scratch_for_texture (cairo_gl_context_t   *ctx,
 {
     cairo_gl_surface_t *surface;
 
-    assert (width <= ctx->max_framebuffer_size && height <= ctx->max_framebuffer_size);
+    if (! valid_size (ctx, width, height))
+	return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_SIZE));
+
     surface = calloc (1, sizeof (cairo_gl_surface_t));
     if (unlikely (surface == NULL))
 	return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
diff --git a/test/Makefile.sources b/test/Makefile.sources
index d44edb4..509c11c 100644
--- a/test/Makefile.sources
+++ b/test/Makefile.sources
@@ -394,6 +394,7 @@ ft_font_test_sources = \
 
 gl_surface_test_sources = \
 	gl-device-release.c \
+	gl-oversized-surface.c \
 	gl-surface-source.c
 
 quartz_surface_test_sources = quartz-surface-source.c
diff --git a/test/gl-oversized-surface.c b/test/gl-oversized-surface.c
new file mode 100644
index 0000000..507f388
--- /dev/null
+++ b/test/gl-oversized-surface.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright © 2012 Igalia S.L.
+ * Copyright © 2009 Eric Anholt
+ * Copyright © 2009 Chris Wilson
+ * Copyright © 2005 Red Hat, Inc
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Chris Wilson not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Chris Wilson makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * IGALIA S.L. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Martin Robinson <mrobinson at igalia.com>
+ */
+
+#include "cairo-test.h"
+#include <cairo-gl.h>
+#include <assert.h>
+#include <limits.h>
+
+static cairo_test_status_t
+preamble (cairo_test_context_t *test_ctx)
+{
+    int rgba_attribs[] = {
+	GLX_RGBA,
+	GLX_RED_SIZE, 1,
+	GLX_GREEN_SIZE, 1,
+	GLX_BLUE_SIZE, 1,
+	GLX_ALPHA_SIZE, 1,
+	GLX_DOUBLEBUFFER,
+	None
+    };
+
+    Display *display;
+    XVisualInfo *visual_info;
+    GLXContext glx_context;
+    cairo_device_t *device;
+    cairo_surface_t *oversized_surface;
+
+    display = XOpenDisplay (NULL);
+    if (display == NULL)
+	return CAIRO_TEST_UNTESTED;
+
+    visual_info = glXChooseVisual (display, DefaultScreen (display), rgba_attribs);
+    if (visual_info == NULL) {
+	XCloseDisplay (display);
+	return CAIRO_TEST_UNTESTED;
+    }
+
+    glx_context = glXCreateContext (display, visual_info, NULL, True);
+    if (glx_context == NULL) {
+	XCloseDisplay (display);
+	return CAIRO_TEST_UNTESTED;
+    }
+
+    device = cairo_glx_device_create (display, glx_context);
+
+    oversized_surface = cairo_gl_surface_create (device, CAIRO_CONTENT_COLOR_ALPHA, INT_MAX, INT_MAX);
+    assert (cairo_surface_status (oversized_surface) == CAIRO_STATUS_INVALID_SIZE);
+
+    cairo_device_destroy (device);
+    glXDestroyContext(display, glx_context);
+    XCloseDisplay (display);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (gl_oversized_surface,
+	    "Test that creating a surface beyond texture limits results in an error surface",
+	    "gl", /* keywords */
+	    NULL, /* requirements */
+	    0, 0,
+	    preamble, NULL)
-- 
1.8.1.2