Properly handle failures of Xv query functions.

If one of the query functions fail, xvinfo does not properly handle
these cases and will most likely run into a segmentation fault due
to accessing uninitialized variables (which includes pointers).

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/xvinfo.c b/xvinfo.c
index 891c8c2..db1a008 100644
--- a/xvinfo.c
+++ b/xvinfo.c
@@ -71,7 +71,7 @@ main(int argc, char *argv[])
         exit(-1);
     }
 
-    if ((Success != XvQueryExtension(dpy, &ver, &rev, &reqB, &eventB, &errorB))) {
+    if (Success != XvQueryExtension(dpy, &ver, &rev, &reqB, &eventB, &errorB)) {
         fprintf(stderr, "%s: No X-Video Extension on %s\n", progname,
                 (disname != NULL) ? disname : XDisplayName(NULL));
         exit(0);
@@ -84,7 +84,12 @@ main(int argc, char *argv[])
 
     for (i = 0; i < nscreens; i++) {
         fprintf(stdout, "screen #%i\n", i);
-        XvQueryAdaptors(dpy, RootWindow(dpy, i), &nadaptors, &ainfo);
+        if (Success != XvQueryAdaptors(dpy, RootWindow(dpy, i), &nadaptors,
+                                       &ainfo)) {
+            fprintf(stderr, "%s:  Failed to query adaptors on display %s\n",
+                    progname, (disname != NULL) ? disname : XDisplayName(NULL));
+            exit(-1);
+        }
 
         if (!nadaptors) {
             fprintf(stdout, " no adaptors present\n");
@@ -178,7 +183,14 @@ main(int argc, char *argv[])
                 fprintf(stdout, "    no port attributes defined\n");
             }
 
-            XvQueryEncodings(dpy, ainfo[j].base_id, &nencode, &encodings);
+            if (Success != XvQueryEncodings(dpy, ainfo[j].base_id, &nencode,
+                                            &encodings)) {
+                fprintf(stderr,
+                        "%s:  Failed to query encodings on display %s\n",
+                        progname,
+                        (disname != NULL) ? disname : XDisplayName(NULL));
+                exit(-1);
+            }
 
             if (encodings && nencode) {
                 unsigned int ImageEncodings = 0;