1 files changed, 54 insertions, 6 deletions

diff --git a/src/textconv.c b/src/textconv.c
index d8166bcfd03..9003816e191 100644
--- a/src/textconv.c
+++ b/src/textconv.c
@@ -36,6 +36,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "buffer.h"
 #include "syntax.h"
 #include "blockinput.h"
+#include "keyboard.h"
 
 
 
@@ -522,7 +523,11 @@ detect_conversion_events (void)
 
   FOR_EACH_FRAME (tail, frame)
     {
-      if (XFRAME (frame)->conversion.actions)
+      /* See if there's a pending edit on this frame.  */
+      if (XFRAME (frame)->conversion.actions
+          && ((XFRAME (frame)->conversion.actions->operation
+               != TEXTCONV_BARRIER)
+              || (kbd_fetch_ptr == kbd_store_ptr)))
         return true;
     }
 
@@ -740,7 +745,7 @@ really_set_composing_text (struct frame *f, ptrdiff_t position,
       Fset_marker_insertion_type (f->conversion.compose_region_end,
                                   Qt);
 
-      start = position;
+      start = PT;
     }
   else
     {
@@ -762,7 +767,7 @@ really_set_composing_text (struct frame *f, ptrdiff_t position,
     record_buffer_change (start, PT, Qnil);
 
   /* Now move point to an appropriate location.  */
-  if (position < 0)
+  if (position <= 0)
     {
       wanted = start;
 
@@ -1198,6 +1203,19 @@ handle_pending_conversion_events_1 (struct frame *f,
     case TEXTCONV_REQUEST_POINT_UPDATE:
       really_request_point_update (f);
       break;
+
+    case TEXTCONV_BARRIER:
+      if (kbd_fetch_ptr != kbd_store_ptr)
+        emacs_abort ();
+
+      /* Once a barrier is hit, synchronize F's selected window's
+         `ephemeral_last_point' with its current point.  The reason
+         for this is because otherwise a previous keyboard event may
+         have taken place without redisplay happening in between.  */
+
+      if (w)
+        w->ephemeral_last_point = window_point (w);
+      break;
     }
 
   /* Signal success.  */
@@ -1231,7 +1249,7 @@ handle_pending_conversion_events (void)
   static int inside;
   specpdl_ref count;
   ptrdiff_t last_point;
-  struct window *w;
+  struct window *w, *w1;
 
   handled = false;
 
@@ -1242,8 +1260,6 @@ handle_pending_conversion_events (void)
     Vtext_conversion_edits = Qnil;
 
   inside++;
-  last_point = -1;
-  w = NULL;
 
   count = SPECPDL_INDEX ();
   record_unwind_protect_ptr (decrement_inside, &inside);
@@ -1251,6 +1267,8 @@ handle_pending_conversion_events (void)
   FOR_EACH_FRAME (tail, frame)
     {
       f = XFRAME (frame);
+      last_point = -1;
+      w = NULL;
 
       /* Test if F has any outstanding conversion events.  Then
          process them in bottom to up order.  */
@@ -1283,6 +1301,13 @@ handle_pending_conversion_events (void)
           if (!action)
             break;
 
+          /* If action is a barrier event and the keyboard buffer is
+             not yet empty, break out of the loop.  */
+
+          if (action->operation == TEXTCONV_BARRIER
+              && kbd_store_ptr != kbd_fetch_ptr)
+            break;
+
           /* Unlink this action.  */
           next = action->next;
           f->conversion.actions = next;
@@ -1515,6 +1540,29 @@ request_point_update (struct frame *f, unsigned long counter)
   input_pending = true;
 }
 
+/* Request that text conversion on F pause until the keyboard buffer
+   becomes empty.
+
+   Use this function to ensure that edits associated with a keyboard
+   event complete before the text conversion edits after the barrier
+   take place.  */
+
+void
+textconv_barrier (struct frame *f, unsigned long counter)
+{
+  struct text_conversion_action *action, **last;
+
+  action = xmalloc (sizeof *action);
+  action->operation = TEXTCONV_BARRIER;
+  action->data = Qnil;
+  action->next = NULL;
+  action->counter = counter;
+  for (last = &f->conversion.actions; *last; last = &(*last)->next)
+    ;;
+  *last = action;
+  input_pending = true;
+}
+
 /* Return N characters of text around point in F's old selected
    window.