Mesa (master): egl: Fix a false negative check in _eglCheckMakeCurrent.

[Chia-I Wu]

Module: Mesa
Branch: master
Commit: 0d43cbed2f130c377bed92c7a8ad8c19f441d6a5
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0d43cbed2f130c377bed92c7a8ad8c19f441d6a5

Author: Chia-I Wu <olv at lunarg.com>
Date:   Sat Oct 23 16:51:01 2010 +0800

egl: Fix a false negative check in _eglCheckMakeCurrent.

This call sequence

  eglMakeCurrent(dpy, surf, surf, ctx1);
  eglMakeCurrent(dpy, surf, surf, ctx2);

should be valid if ctx1 and ctx2 have the same client API and are not
current in another thread.

---

 src/egl/main/eglcontext.c |   21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/egl/main/eglcontext.c b/src/egl/main/eglcontext.c
index 3266a75..33dcfa6 100644
--- a/src/egl/main/eglcontext.c
+++ b/src/egl/main/eglcontext.c
@@ -249,10 +249,6 @@ _eglCheckMakeCurrent(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read)
    if (!surfaceless && (draw == NULL || read == NULL))
       return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 
-   /* context stealing from another thread is not allowed */
-   if (ctx->Binding && ctx->Binding != t)
-      return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
-
    /*
     * The spec says
     *
@@ -260,16 +256,23 @@ _eglCheckMakeCurrent(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read)
     * bound to contexts in another thread, an EGL_BAD_ACCESS error is
     * generated."
     *
-    * But it also says
+    * and
     *
     * "at most one context may be bound to a particular surface at a given
     * time"
-    *
-    * The latter is more restrictive so we can check only the latter case.
     */
-   if ((draw && draw->CurrentContext && draw->CurrentContext != ctx) ||
-       (read && read->CurrentContext && read->CurrentContext != ctx))
+   if (ctx->Binding && ctx->Binding != t)
       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
+   if (draw && draw->CurrentContext && draw->CurrentContext != ctx) {
+      if (draw->CurrentContext->Binding != t ||
+          draw->CurrentContext->ClientAPI != ctx->ClientAPI)
+         return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
+   }
+   if (read && read->CurrentContext && read->CurrentContext != ctx) {
+      if (read->CurrentContext->Binding != t ||
+          read->CurrentContext->ClientAPI != ctx->ClientAPI)
+         return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
+   }
 
    /* simply require the configs to be equal */
    if ((draw && draw->Config != ctx->Config) ||