[Mesa-dev] [PATCH] xlib: do not cache return value of glXChooseVisual/glXGetVisualFromFBConfig

[John Sheu]

The returned XVisualInfo from glXChooseVisual/glXGetVisualFromFBConfig
is being cached in XMesaVisual.vishandle (and unconditionally
overwritten on subsequent calls).  However, these entry points are
specified to return XVisualInfo instances to be owned by the caller and
freed with XFree(), so the return values should not be retained.
---
 src/mesa/drivers/x11/fakeglx.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/src/mesa/drivers/x11/fakeglx.c b/src/mesa/drivers/x11/fakeglx.c
index 2f4d9669..d62d5abd 100644
--- a/src/mesa/drivers/x11/fakeglx.c
+++ b/src/mesa/drivers/x11/fakeglx.c
@@ -1241,16 +1241,11 @@ Fake_glXChooseVisual( Display *dpy, int screen, int *list )
 
    xmvis = choose_visual(dpy, screen, list, GL_FALSE);
    if (xmvis) {
-#if 0
-      return xmvis->vishandle;
-#else
-      /* create a new vishandle - the cached one may be stale */
-      xmvis->vishandle = malloc(sizeof(XVisualInfo));
-      if (xmvis->vishandle) {
-         memcpy(xmvis->vishandle, xmvis->visinfo, sizeof(XVisualInfo));
+      XVisualInfo* visinfo = malloc(sizeof(XVisualInfo));
+      if (visinfo) {
+         memcpy(visinfo, xmvis->visinfo, sizeof(XVisualInfo));
       }
-      return xmvis->vishandle;
-#endif
+      return visinfo;
    }
    else
       return NULL;
@@ -1974,16 +1969,11 @@ Fake_glXGetVisualFromFBConfig( Display *dpy, GLXFBConfig config )
 {
    if (dpy && config) {
       XMesaVisual xmvis = (XMesaVisual) config;
-#if 0      
-      return xmvis->vishandle;
-#else
-      /* create a new vishandle - the cached one may be stale */
-      xmvis->vishandle = malloc(sizeof(XVisualInfo));
-      if (xmvis->vishandle) {
-         memcpy(xmvis->vishandle, xmvis->visinfo, sizeof(XVisualInfo));
+      XVisualInfo* visinfo = malloc(sizeof(XVisualInfo));
+      if (visinfo) {
+         memcpy(visinfo, xmvis->visinfo, sizeof(XVisualInfo));
       }
-      return xmvis->vishandle;
-#endif
+      return visinfo;
    }
    else {
       return NULL;
-- 
2.8.0.rc3.226.g39d4020