[PATCHv5 1/4] `kill-buffer' runs query functions before checking buffer modification.

[Michal Nazarewicz]

From: Michal Nazarewicz <address@hidden>

* buffer.c (FKill_buffer): Run `kill-buffer-query-functions'
before checking whether buffer is modified.  This lets
`kill-buffer-query-functions' cancel killing of the buffer or save
its content before `kill-buffer' asks user the "Buffer %s
modified; kill anyway?" question.
---
 doc/lispref/buffers.texi |  2 +-
 src/ChangeLog            |  8 ++++++++
 src/buffer.c             | 28 ++++++++++++++++------------
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/doc/lispref/buffers.texi b/doc/lispref/buffers.texi
index 7ed1876..e79c86d 100644
--- a/doc/lispref/buffers.texi
+++ b/doc/lispref/buffers.texi
@@ -1064,7 +1064,7 @@ Buffer foo.changed modified; kill anyway? (yes or no) 
@kbd{yes}
 @end deffn
 
 @defvar kill-buffer-query-functions
-After confirming unsaved changes, @code{kill-buffer} calls the functions
+Before confirming unsaved changes, @code{kill-buffer} calls the functions
 in the list @code{kill-buffer-query-functions}, in order of appearance,
 with no arguments.  The buffer being killed is the current buffer when
 they are called.  The idea of this feature is that these functions will
diff --git a/src/ChangeLog b/src/ChangeLog
index e404cdb..a3af8d1 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,11 @@
+2013-06-28  Michal Nazarewicz  <address@hidden>
+
+       * buffer.c (FKill_buffer): Run `kill-buffer-query-functions'
+       before checking whether buffer is modified.  This lets
+       `kill-buffer-query-functions' cancel killing of the buffer or save
+       its content before `kill-buffer' asks user the "Buffer %s
+       modified; kill anyway?" question.
+
 2013-06-28  Paul Eggert  <address@hidden>
 
        * image.c (x_from_xcolors): Remove unused local.
diff --git a/src/buffer.c b/src/buffer.c
index 08299da..ad670e0 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1734,18 +1734,6 @@ cleaning up all windows currently displaying the buffer 
to be killed. */)
   if (!BUFFER_LIVE_P (b))
     return Qnil;
 
-  /* Query if the buffer is still modified.  */
-  if (INTERACTIVE && !NILP (BVAR (b, filename))
-      && BUF_MODIFF (b) > BUF_SAVE_MODIFF (b))
-    {
-      GCPRO1 (buffer);
-      tem = do_yes_or_no_p (format2 ("Buffer %s modified; kill anyway? ",
-                                    BVAR (b, name), make_number (0)));
-      UNGCPRO;
-      if (NILP (tem))
-       return Qnil;
-    }
-
   /* Run hooks with the buffer to be killed the current buffer.  */
   {
     ptrdiff_t count = SPECPDL_INDEX ();
@@ -1761,6 +1749,22 @@ cleaning up all windows currently displaying the buffer 
to be killed. */)
     if (NILP (tem))
       return unbind_to (count, Qnil);
 
+    /* Query if the buffer is still modified.  */
+    if (INTERACTIVE && !NILP (BVAR (b, filename))
+       && BUF_MODIFF (b) > BUF_SAVE_MODIFF (b))
+      {
+        GCPRO1 (buffer);
+        tem = do_yes_or_no_p (format2 ("Buffer %s modified; kill anyway? ",
+                                      BVAR (b, name), make_number (0)));
+       UNGCPRO;
+       if (NILP (tem))
+         return unbind_to (count, Qnil);
+      }
+
+    /* If the hooks have killed the buffer, exit now.  */
+    if (!BUFFER_LIVE_P (b))
+      return unbind_to (count, Qt);
+
     /* Then run the hooks.  */
     Frun_hooks (1, &Qkill_buffer_hook);
     unbind_to (count, Qnil);
-- 
1.8.3.1