Mesa (master): vbo: fix offset in minmax cache key

[Charmaine Lee]

Module: Mesa
Branch: master
Commit: 2d93b462b4d978b0da417b35a7470e336bc4e783
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=2d93b462b4d978b0da417b35a7470e336bc4e783

Author: Charmaine Lee <charmainel at vmware.com>
Date:   Wed Aug 30 14:26:41 2017 -0700

vbo: fix offset in minmax cache key

Instead of saving primitive offset in the minmax cache key,
save the actual buffer offset which is used in the cache lookup.

Fixes rendering artifact seen with GoogleEarth when run with
VMware driver.

v2: Per Brian's comment, initialize offset to avoid compiler warning.

Cc: mesa-stable at lists.freedesktop.org
Reviewed-by: Brian Paul <brianp at vmware.com>

---

 src/mesa/vbo/vbo_minmax_index.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/mesa/vbo/vbo_minmax_index.c b/src/mesa/vbo/vbo_minmax_index.c
index 4c17a08662..58a2af49ac 100644
--- a/src/mesa/vbo/vbo_minmax_index.c
+++ b/src/mesa/vbo/vbo_minmax_index.c
@@ -245,6 +245,7 @@ vbo_get_minmax_index(struct gl_context *ctx,
       _mesa_primitive_restart_index(ctx, ib->index_size);
    const char *indices;
    GLuint i;
+   GLintptr offset = 0;
 
    indices = (char *) ib->ptr + prim->start * ib->index_size;
    if (_mesa_is_bufferobj(ib->obj)) {
@@ -254,7 +255,8 @@ vbo_get_minmax_index(struct gl_context *ctx,
                                 count, min_index, max_index))
          return;
 
-      indices = ctx->Driver.MapBufferRange(ctx, (GLintptr) indices, size,
+      offset = indices;
+      indices = ctx->Driver.MapBufferRange(ctx, offset, size,
                                            GL_MAP_READ_BIT, ib->obj,
                                            MAP_INTERNAL);
    }
@@ -337,8 +339,8 @@ vbo_get_minmax_index(struct gl_context *ctx,
    }
 
    if (_mesa_is_bufferobj(ib->obj)) {
-      vbo_minmax_cache_store(ctx, ib->obj, ib->index_size, prim->start, count,
-                             *min_index, *max_index);
+      vbo_minmax_cache_store(ctx, ib->obj, ib->index_size, offset,
+                             count, *min_index, *max_index);
       ctx->Driver.UnmapBuffer(ctx, ib->obj, MAP_INTERNAL);
    }
 }