From 2394d20dafdfa308d494fc739c63c6a4e91c8185 Mon Sep 17 00:00:00 2001
From: "Xiang, Haihao" <haihao.xiang@intel.com>
Date: Mon, 30 Jul 2007 23:50:52 +0800
Subject: [PATCH] Fix an error in _mesa_validate_DrawElements

The field 'Data' in an obj is NULL in some dri drivers(such
as i965). Use mapped pointer instead.
---
 src/mesa/main/api_validate.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 841c6a5..18dead6 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -35,6 +35,7 @@ _mesa_validate_DrawElements(GLcontext *ctx,
 			    GLenum mode, GLsizei count, GLenum type,
 			    const GLvoid *indices)
 {
+   GLboolean mapped = GL_FALSE;
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx,  GL_FALSE);
 
    if (count <= 0) {
@@ -67,13 +68,19 @@ _mesa_validate_DrawElements(GLcontext *ctx,
    /* Vertex buffer object tests */
    if (ctx->Array.ElementArrayBufferObj->Name) {
       GLuint indexBytes;
+      const GLvoid *map = ctx->Driver.MapBuffer(ctx,
+                                                GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                                GL_READ_ONLY,
+                                                ctx->Array.ElementArrayBufferObj);
 
       /* use indices in the buffer object */
-      if (!ctx->Array.ElementArrayBufferObj->Data) {
+      if (!map) {
          _mesa_warning(ctx, "DrawElements with empty vertex elements buffer!");
          return GL_FALSE;
       }
 
+      mapped = GL_TRUE;
+
       /* make sure count doesn't go outside buffer bounds */
       if (type == GL_UNSIGNED_INT) {
          indexBytes = count * sizeof(GLuint);
@@ -86,18 +93,18 @@ _mesa_validate_DrawElements(GLcontext *ctx,
          indexBytes = count * sizeof(GLushort);
       }
 
-      if ((GLubyte *) indices + indexBytes >
-          ctx->Array.ElementArrayBufferObj->Data +
-          ctx->Array.ElementArrayBufferObj->Size) {
+      if (ADD_POINTERS(map, indices) + indexBytes > 
+          (GLubyte *)map + ctx->Array.ElementArrayBufferObj->Size) {
          _mesa_warning(ctx, "glDrawElements index out of buffer bounds");
+         ctx->Driver.UnmapBuffer(ctx,
+                                 GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                 ctx->Array.ElementArrayBufferObj);
          return GL_FALSE;
       }
 
       /* Actual address is the sum of pointers.  Indices may be used below. */
       if (ctx->Const.CheckArrayBounds) {
-         indices = (const GLvoid *)
-            ADD_POINTERS(ctx->Array.ElementArrayBufferObj->Data,
-                         (const GLubyte *) indices);
+         indices = ADD_POINTERS(map, indices);
       }
    }
    else {
@@ -126,12 +133,25 @@ _mesa_validate_DrawElements(GLcontext *ctx,
             if (((GLubyte *) indices)[i] > max)
                max = ((GLubyte *) indices)[i];
       }
+
       if (max >= ctx->Array._MaxElement) {
          /* the max element is out of bounds of one or more enabled arrays */
+         if (mapped) {
+            ctx->Driver.UnmapBuffer(ctx,
+                                    GL_ELEMENT_ARRAY_BUFFER_ARB,
+                                    ctx->Array.ElementArrayBufferObj);
+         }
+
          return GL_FALSE;
       }
    }
 
+   if (mapped) {
+      ctx->Driver.UnmapBuffer(ctx,
+                              GL_ELEMENT_ARRAY_BUFFER_ARB,
+                              ctx->Array.ElementArrayBufferObj);
+   }
+
    return GL_TRUE;
 }
 
-- 
2.7.4