[Mesa-dev] [PATCH] Fix glGetInteger*(GL_SAMPLER_BINDING).

[Alan Hourihane]

If the sampler object has been deleted on another context, an
alternative context may reference the old sampler. So ensure the sampler
object still exists.

Signed-off-by: Alan Hourihane <alanh at vmware.com>
---
  src/mesa/main/get.c        |   12 +++++++++++-
  src/mesa/main/samplerobj.c |    2 +-
  src/mesa/main/samplerobj.h |    2 ++
  3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/get.c b/src/mesa/main/get.c
index 2399f9c..c627dd6 100644
--- a/src/mesa/main/get.c
+++ b/src/mesa/main/get.c
@@ -34,6 +34,7 @@
  #include "state.h"
  #include "texcompress.h"
  #include "framebuffer.h"
+#include "samplerobj.h"

  /* This is a table driven implemetation of the glGet*v() functions.
   * The basic idea is that most getters just look up an int somewhere
@@ -827,7 +828,16 @@ find_custom_value(struct gl_context *ctx, const 
struct valu
e_desc *d, union valu
        {
           struct gl_sampler_object *samp =
ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler;
-         v->value_int = samp ? samp->Name : 0;
+
+         /*
+      * The sampler object may have been deleted on another context,
+      * so we try to lookup the sampler object before returning it's Name.
+      */
+     if (samp && _mesa_lookup_samplerobj(ctx, samp->Name)) {
+        v->value_int = samp->Name;
+     } else {
+        v->value_int = 0;
+     }
        }
        break;
     /* GL_ARB_uniform_buffer_object */
diff --git a/src/mesa/main/samplerobj.c b/src/mesa/main/samplerobj.c
index 4664cc3..5cff329 100644
--- a/src/mesa/main/samplerobj.c
+++ b/src/mesa/main/samplerobj.c
@@ -40,7 +40,7 @@
  #include "main/samplerobj.h"


-static struct gl_sampler_object *
+struct gl_sampler_object *
  _mesa_lookup_samplerobj(struct gl_context *ctx, GLuint name)
  {
     if (name == 0)
diff --git a/src/mesa/main/samplerobj.h b/src/mesa/main/samplerobj.h
index 3114257..69e3899 100644
--- a/src/mesa/main/samplerobj.h
+++ b/src/mesa/main/samplerobj.h
@@ -62,6 +62,8 @@ _mesa_reference_sampler_object(struct gl_context *ctx,
        _mesa_reference_sampler_object_(ctx, ptr, samp);
  }

+extern struct gl_sampler_object *
+_mesa_lookup_samplerobj(struct gl_context *ctx, GLuint name);

  extern struct gl_sampler_object *
  _mesa_new_sampler_object(struct gl_context *ctx, GLuint name);
-- 
1.7.8.6