master 1472b046ea: * src/xterm.c (x_term_init): Avoid freeze with 24-bit visuals.

[Po Lu]

branch: master
commit 1472b046eaeb8b2177341fb1c2b42bf5d1207ec7
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    * src/xterm.c (x_term_init): Avoid freeze with 24-bit visuals.
---
 src/xterm.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/xterm.c b/src/xterm.c
index dc4e53759e..12f3c0a9d1 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -15578,9 +15578,13 @@ x_term_init (Lisp_Object display_name, char 
*xrm_option, char *resource_name)
 #ifdef HAVE_XRENDER
       if (dpyinfo->pict_format)
        {
-         get_bits_and_offset (((unsigned long) 
dpyinfo->pict_format->direct.alphaMask
-                               << dpyinfo->pict_format->direct.alpha),
-                              &dpyinfo->alpha_bits, &dpyinfo->alpha_offset);
+         unsigned long channel_mask
+           = ((unsigned long) dpyinfo->pict_format->direct.alphaMask
+              << dpyinfo->pict_format->direct.alpha);
+
+         if (channel_mask)
+           get_bits_and_offset (channel_mask, &dpyinfo->alpha_bits,
+                                &dpyinfo->alpha_offset);
        }
       else
 #endif