* process.c (exec_sentinel): Preserve current-buffer.

src/ChangeLog

 2010-04-11  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+	* process.c (exec_sentinel): Preserve current-buffer.
+
 	* process.c (read_process_output): Move the save-current-buffer to
 	apply to both the filter and the non-filter branches.
 

src/process.c

@@ -6840,6 +6840,11 @@ exec_sentinel (proc, reason)
   XSETBUFFER (obuffer, current_buffer);
   okeymap = current_buffer->keymap;
 
+  /* There's no good reason to let sentinels change the current
+     buffer, and many callers of accept-process-output, sit-for, and
+     friends don't expect current-buffer to be changed from under them.  */
+  record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+
   sentinel = p->sentinel;
   if (NILP (sentinel))
     return;