xmlIO: Fix an FD leak on gzdopen() failure

According to the documentation, gzdopen() does not close the FD on
failure (but does effectively close it on success, since gzclose()
closes it).

Coverity issues: #60440, #60441

https://bugzilla.gnome.org/show_bug.cgi?id=731990

1 files changed, 12 insertions, 2 deletions

diff --git a/xmlIO.c b/xmlIO.c
index d1544f3d..5baeba33 100644
--- a/xmlIO.c
+++ b/xmlIO.c
@@ -1159,7 +1159,12 @@ xmlGzfileOpen_real (const char *filename) {
     gzFile fd;
 
     if (!strcmp(filename, "-")) {
-        fd = gzdopen(dup(fileno(stdin)), "rb");
+        int duped_fd = dup(fileno(stdin));
+        fd = gzdopen(duped_fd, "rb");
+        if (fd == Z_NULL) {
+            close(duped_fd);  /* gzdOpen() does not close on failure */
+        }
+
 	return((void *) fd);
     }
 
@@ -1233,7 +1238,12 @@ xmlGzfileOpenW (const char *filename, int compression) {
 
     snprintf(mode, sizeof(mode), "wb%d", compression);
     if (!strcmp(filename, "-")) {
-        fd = gzdopen(dup(fileno(stdout)), mode);
+        int duped_fd = dup(fileno(stdout));
+        fd = gzdopen(duped_fd, "rb");
+        if (fd == Z_NULL) {
+            close(duped_fd);  /* gzdOpen() does not close on failure */
+        }
+
 	return((void *) fd);
     }