From 911482e5ae88ba26a1b3290731968f8b8a80cd70 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 22 May 2009 23:44:27 +0100
Subject: [PATCH] [gl] Constrain image sources to max texture size

---
 src/cairo-gl-private.h |  2 ++
 src/cairo-gl-surface.c | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/cairo-gl-private.h b/src/cairo-gl-private.h
index 47ebd01d9..3d37fe091 100644
--- a/src/cairo-gl-private.h
+++ b/src/cairo-gl-private.h
@@ -65,6 +65,8 @@ struct _cairo_gl_context {
 
     cairo_mutex_t mutex; /* needed? */
     GLuint dummy_tex;
+    GLint max_framebuffer_size;
+    GLint max_texture_size;
 
     cairo_gl_surface_t *current_target;
 
diff --git a/src/cairo-gl-surface.c b/src/cairo-gl-surface.c
index d54c0a206..df130f84e 100644
--- a/src/cairo-gl-surface.c
+++ b/src/cairo-gl-surface.c
@@ -130,6 +130,11 @@ _cairo_gl_context_init (cairo_gl_context_t *ctx)
     glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0,
 		  GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 
+    ctx->max_framebuffer_size = 0;
+    glGetIntegerv (GL_MAX_RENDERBUFFER_SIZE, &ctx->max_framebuffer_size);
+    ctx->max_texture_size = 0;
+    glGetIntegerv (GL_MAX_TEXTURE_SIZE, &ctx->max_texture_size);
+
     return CAIRO_STATUS_SUCCESS;
 }
 
@@ -459,6 +464,9 @@ cairo_gl_surface_create (cairo_gl_context_t   *ctx,
     if (ctx->status)
 	return _cairo_surface_create_in_error (ctx->status);
 
+    if (width > ctx->max_framebuffer_size || height > ctx->max_framebuffer_size)
+	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));
@@ -584,6 +592,12 @@ _cairo_gl_surface_create_similar (void		 *abstract_surface,
 
     assert (CAIRO_CONTENT_VALID (content));
 
+    if (width > surface->ctx->max_framebuffer_size ||
+	height > surface->ctx->max_framebuffer_size)
+    {
+	return NULL;
+    }
+
     if (width < 1)
 	width = 1;
     if (height < 1)
@@ -946,6 +960,11 @@ _cairo_gl_pattern_image_texture_setup (cairo_gl_composite_operand_t *operand,
 	return CAIRO_INT_STATUS_UNSUPPORTED;
 
     image_surface = (cairo_image_surface_t *)surface_pattern->surface;
+    if (image_surface->width > dst->ctx->max_texture_size ||
+	image_surface->height > dst->ctx->max_texture_size)
+    {
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+    }
 
     /* The textures we create almost always has appropriate alpha channel
      * contents.  But sometimes GL sucks at image specification and we end up