1 files changed, 36 insertions, 8 deletions

diff --git a/src/process.c b/src/process.c
index e74e1ed7b56..1637ab6e7db 100644
--- a/src/process.c
+++ b/src/process.c
@@ -2078,11 +2078,11 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
           EMACS_SET_SECS_USECS (timeout, 100000, 0);
         }
 
-      /* If our caller will not immediately handle keyboard events,
-         run timer events directly.
-         (Callers that will immediately read keyboard events
-         call timer_delay on their own.)  */
-      if (1)
+      /* Normally we run timers here.
+         But not if wait_for_cell; in those cases,
+         the wait is supposed to be short,
+         and those callers cannot handle running arbitrary Lisp code here.  */
+      if (! wait_for_cell)
         {
           EMACS_TIME timer_delay;
           int old_timers_run;
@@ -2248,7 +2248,7 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
       /* If there is any, return immediately
          to give it higher priority than subprocesses */
 
-      if ((XINT (read_kbd) != 0 || wait_for_cell)
+      if ((XINT (read_kbd) != 0)
           && detect_input_pending_run_timers (do_display))
         {
           swallow_events (do_display);
@@ -2256,6 +2256,20 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
             break;
         }
 
+      /* If wait_for_cell. check for keyboard input
+         but don't run any timers.
+         ??? (It seems wrong to me to check for keyboard
+         input at all when wait_for_cell, but the code
+         has been this way since July 1994.
+         Try changing this after version 19.31.)  */
+      if (wait_for_cell
+          && detect_input_pending ())
+        {
+          swallow_events (do_display);
+          if (detect_input_pending ())
+            break;
+        }
+
       /* Exit now if the cell we're waiting for became non-nil.  */
       if (wait_for_cell && ! NILP (*wait_for_cell))
         break;
@@ -3903,7 +3917,7 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
          run timer events directly.
          (Callers that will immediately read keyboard events
          call timer_delay on their own.)  */
-      if (1)
+      if (! wait_for_cell)
         {
           EMACS_TIME timer_delay;
           int old_timers_run;
@@ -3995,7 +4009,7 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
 
       /* Check for keyboard input */
 
-      if ((XINT (read_kbd) != 0 || wait_for_cell)
+      if ((XINT (read_kbd) != 0)
           && detect_input_pending_run_timers (do_display))
         {
           swallow_events (do_display);
@@ -4003,6 +4017,20 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
             break;
         }
 
+      /* If wait_for_cell. check for keyboard input
+         but don't run any timers.
+         ??? (It seems wrong to me to check for keyboard
+         input at all when wait_for_cell, but the code
+         has been this way since July 1994.
+         Try changing this after version 19.31.)  */
+      if (wait_for_cell
+          && detect_input_pending ())
+        {
+          swallow_events (do_display);
+          if (detect_input_pending ())
+            break;
+        }
+
       /* Exit now if the cell we're waiting for became non-nil.  */
       if (wait_for_cell && ! NILP (*wait_for_cell))
         break;