[Emacs-diffs] emacs-25 3f042f6: Improve commentary of prepare_to_modify_buffer_1

[Eli Zaretskii]

branch: emacs-25
commit 3f042f65887672da52c6fe32b6d3254aff4be9c7
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Improve commentary of prepare_to_modify_buffer_1
    
    * src/insdel.c (prepare_to_modify_buffer_1): Mention in commentary
    that this function runs Lisp.  Suggested by Richard Stallman
    <address@hidden>.
---
 src/insdel.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/src/insdel.c b/src/insdel.c
index 8b08c1e..bb3171b 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1785,7 +1785,12 @@ 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,