Don't install keyboard hook when debugged on MS-Windows

[gnu-emacs] / src / insdel.c

diff --git a/src/insdel.c b/src/insdel.c
index 8b08c1e59b74bd84faa1ca0da8a4705783b98fc8..4ad1074f5f79bf94e7c47f72f92b5aa0132bcd5e 100644 (file)
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1,13 +1,13 @@
 /* Buffer insertion/deletion and gap motion for GNU Emacs.
-   Copyright (C) 1985-1986, 1993-1995, 1997-2015 Free Software
+   Copyright (C) 1985-1986, 1993-1995, 1997-2016 Free Software
    Foundation, Inc.
 
 This file is part of GNU Emacs.
 
 GNU Emacs is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -126,7 +126,10 @@ gap_left (ptrdiff_t charpos, ptrdiff_t bytepos, bool newgap)
       if (i == 0)
        break;
       /* If a quit is requested, stop copying now.
-        Change BYTEPOS to be where we have actually moved the gap to.  */
+        Change BYTEPOS to be where we have actually moved the gap to.
+        Note that this cannot happen when we are called to make the
+        gap larger or smaller, since make_gap_larger and
+        make_gap_smaller prevent QUIT by setting inhibit-quit.  */
       if (QUITP)
        {
          bytepos = new_s1;
@@ -179,7 +182,10 @@ gap_right (ptrdiff_t charpos, ptrdiff_t bytepos)
       if (i == 0)
        break;
       /* If a quit is requested, stop copying now.
-        Change BYTEPOS to be where we have actually moved the gap to.  */
+        Change BYTEPOS to be where we have actually moved the gap to.
+        Note that this cannot happen when we are called to make the
+        gap larger or smaller, since make_gap_larger and
+        make_gap_smaller prevent QUIT by setting inhibit-quit.  */
       if (QUITP)
        {
          bytepos = new_s1;
@@ -386,7 +392,9 @@ make_gap_larger (ptrdiff_t nbytes_added)
 
   enlarge_buffer_text (current_buffer, nbytes_added);
 
-  /* Prevent quitting in move_gap.  */
+  /* Prevent quitting in gap_left.  We cannot allow a QUIT there,
+     because that would leave the buffer text in an inconsistent
+     state, with 2 gap holes instead of just one.  */
   tem = Vinhibit_quit;
   Vinhibit_quit = Qt;
 
@@ -432,7 +440,9 @@ make_gap_smaller (ptrdiff_t nbytes_removed)
   if (GAP_SIZE - nbytes_removed < GAP_BYTES_MIN)
     nbytes_removed = GAP_SIZE - GAP_BYTES_MIN;
 
-  /* Prevent quitting in move_gap.  */
+  /* Prevent quitting in gap_right.  We cannot allow a QUIT there,
+     because that would leave the buffer text in an inconsistent
+     state, with 2 gap holes instead of just one.  */
   tem = Vinhibit_quit;
   Vinhibit_quit = Qt;
 
@@ -1785,7 +1795,12 @@ run_undoable_change (void)
    any modification properties the text may have.
 
    If PRESERVE_PTR is nonzero, we relocate *PRESERVE_PTR
-   by holding its value temporarily in a marker.  */
+   by holding its value temporarily in a marker.
+
+   This function runs Lisp, which means it can GC, which means it can
+   compact buffers, including the current buffer being worked on here.
+   So don't you dare calling this function while manipulating the gap,
+   or during some other similar "critical section".  */
 
 void
 prepare_to_modify_buffer_1 (ptrdiff_t start, ptrdiff_t end,