mesa: Check for framebuffer completeness before looking at the rb.

Otherwise, an incomplete framebuffer could have a NULL
_ColorReadBuffer and we'd deref that.

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 31acfcbf13e..1381110495f 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -701,6 +701,12 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
       return;
    }
 
+   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
+                  "glReadPixels(incomplete framebuffer)" );
+      return;
+   }
+
    /* Check that the destination format and source buffer are both
     * integer-valued or both non-integer-valued.
     */
@@ -715,12 +721,6 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
       }
    }
 
-   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
-      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
-                  "glReadPixels(incomplete framebuffer)" );
-      return;
-   }
-
    if (ctx->ReadBuffer->Name != 0 && ctx->ReadBuffer->Visual.samples > 0) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(multisample FBO)");
       return;