xlib: fix glXGetCurrentDisplay() failure

glXGetCurrentDisplay() has been broken for years and nobody noticed until
recently.  This change adds a new XMesaGetCurrentDisplay() that the GLX
emulation API can call, just as we did for glXGetCurrentContext().

Tested by hacking glxgears to call glXGetCurrentContext() before and
after glXMakeCurrent() to verify the return value is NULL beforehand and
the same as the opened display afterward.

Also tested by Tom Hudson with his tests programs.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100988
Cc: [email protected]
Tested-by: Tom Hudson <[email protected]>
Signed-off-by: Brian Paul <[email protected]>
(cherry picked from commit c6ba85a8c0f02b3b7058dae7afb6c49f56567319)

4 files changed, 18 insertions, 5 deletions

diff --git a/src/mesa/drivers/x11/glxapi.c b/src/mesa/drivers/x11/glxapi.c
index a807074a863..52e60265697 100644
--- a/src/mesa/drivers/x11/glxapi.c
+++ b/src/mesa/drivers/x11/glxapi.c
@@ -379,13 +379,13 @@ glXQueryServerString(Display *dpy, int screen, int name)
 
 /*** GLX_VERSION_1_2 ***/
 
+/* declare here to avoid including xmesa.h */
+extern Display *XMesaGetCurrentDisplay(void);
+
 Display PUBLIC *
 glXGetCurrentDisplay(void)
 {
-   /* Same code as in libGL's glxext.c */
-   __GLXcontext *gc = (__GLXcontext *) glXGetCurrentContext();
-   if (NULL == gc) return NULL;
-   return gc->currentDpy;
+   return XMesaGetCurrentDisplay();
 }
 
 
diff --git a/src/mesa/drivers/x11/glxapi.h b/src/mesa/drivers/x11/glxapi.h
index aff38f7531d..cc4f902925b 100644
--- a/src/mesa/drivers/x11/glxapi.h
+++ b/src/mesa/drivers/x11/glxapi.h
@@ -37,7 +37,6 @@
  * work properly.
  */
 typedef struct __GLXcontextRec {
-   Display *currentDpy;
    GLboolean isDirect;
    GLXDrawable currentDrawable;
    GLXDrawable currentReadable;
diff --git a/src/mesa/drivers/x11/xm_api.c b/src/mesa/drivers/x11/xm_api.c
index 5be8aa95de1..155d273236f 100644
--- a/src/mesa/drivers/x11/xm_api.c
+++ b/src/mesa/drivers/x11/xm_api.c
@@ -1304,6 +1304,14 @@ XMesaBuffer XMesaGetCurrentReadBuffer( void )
 }
 
 
+Display *XMesaGetCurrentDisplay(void)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   XMesaContext xmctx = XMESA_CONTEXT(ctx);
+   return xmctx ? xmctx->display : NULL;
+}
+
+
 
 GLboolean XMesaSetFXmode( GLint mode )
 {
diff --git a/src/mesa/drivers/x11/xmesa.h b/src/mesa/drivers/x11/xmesa.h
index cc878e7402e..84b2b27006d 100644
--- a/src/mesa/drivers/x11/xmesa.h
+++ b/src/mesa/drivers/x11/xmesa.h
@@ -241,6 +241,12 @@ extern XMesaBuffer XMesaGetCurrentReadBuffer( void );
 
 
 /*
+ * Return display of current context.
+ */
+extern Display *XMesaGetCurrentDisplay( void );
+
+
+/*
  * Swap the front and back buffers for the given buffer.  No action is
  * taken if the buffer is not double buffered.
  */