1 files changed, 43 insertions, 14 deletions

diff --git a/src/window.c b/src/window.c
index a6648685d4b..d1e3225e198 100644
--- a/src/window.c
+++ b/src/window.c
@@ -3307,6 +3307,25 @@ Fset_window_buffer_unwind (obuf)
 EXFUN (Fset_window_fringes, 4);
 EXFUN (Fset_window_scroll_bars, 4);
 
+void
+run_window_configuration_change_hook (struct frame *f)
+{
+  if (! NILP (Vwindow_configuration_change_hook)
+      && ! NILP (Vrun_hooks))
+    {
+      int count = SPECPDL_INDEX ();
+      if (SELECTED_FRAME () != f)
+        {
+          Lisp_Object frame;
+          XSETFRAME (frame, f);
+          record_unwind_protect (Fselect_frame, Fselected_frame ());
+          Fselect_frame (frame);
+        }
+      call1 (Vrun_hooks, Qwindow_configuration_change_hook);
+      unbind_to (count, Qnil);
+    }
+}
+
 /* Make WINDOW display BUFFER as its contents.  RUN_HOOKS_P non-zero
    means it's allowed to run hooks.  See make_frame for a case where
    it's not allowed.  KEEP_MARGINS_P non-zero means that the current
@@ -3321,6 +3340,7 @@ set_window_buffer (window, buffer, run_hooks_p, keep_margins_p)
   struct window *w = XWINDOW (window);
   struct buffer *b = XBUFFER (buffer);
   int count = SPECPDL_INDEX ();
+  int samebuf = EQ (buffer, w->buffer);
 
   w->buffer = buffer;
 
@@ -3339,16 +3359,28 @@ set_window_buffer (window, buffer, run_hooks_p, keep_margins_p)
   XSETFASTINT (w->window_end_vpos, 0);
   bzero (&w->last_cursor, sizeof w->last_cursor);
   w->window_end_valid = Qnil;
-  w->hscroll = w->min_hscroll = make_number (0);
-  w->vscroll = 0;
-  set_marker_both (w->pointm, buffer, BUF_PT (b), BUF_PT_BYTE (b));
-  set_marker_restricted (w->start,
-                         make_number (b->last_window_start),
-                         buffer);
-  w->start_at_line_beg = Qnil;
-  w->force_start = Qnil;
-  XSETFASTINT (w->last_modified, 0);
-  XSETFASTINT (w->last_overlay_modified, 0);
+  if (!(keep_margins_p && samebuf))
+    { /* If we're not actually changing the buffer, Don't reset hscroll and
+         vscroll.  This case happens for example when called from
+         change_frame_size_1, where we use a dummy call to
+         Fset_window_buffer on the frame's selected window (and no other)
+         just in order to run window-configuration-change-hook.
+         Resetting hscroll and vscroll here is problematic for things like
+         image-mode and doc-view-mode since it resets the image's position
+         whenever we resize the frame.  */
+      w->hscroll = w->min_hscroll = make_number (0);
+      w->vscroll = 0;
+      set_marker_both (w->pointm, buffer, BUF_PT (b), BUF_PT_BYTE (b));
+      set_marker_restricted (w->start,
+                             make_number (b->last_window_start),
+                             buffer);
+      w->start_at_line_beg = Qnil;
+      w->force_start = Qnil;
+      XSETFASTINT (w->last_modified, 0);
+      XSETFASTINT (w->last_overlay_modified, 0);
+    }
+  /* Maybe we could move this into the `if' but it's not obviously safe and
+     I doubt it's worth the trouble.  */
   windows_or_buffers_changed++;
 
   /* We must select BUFFER for running the window-scroll-functions.
@@ -3395,10 +3427,7 @@ set_window_buffer (window, buffer, run_hooks_p, keep_margins_p)
       if (! NILP (Vwindow_scroll_functions))
         run_hook_with_args_2 (Qwindow_scroll_functions, window,
                               Fmarker_position (w->start));
-
-      if (! NILP (Vwindow_configuration_change_hook)
-          && ! NILP (Vrun_hooks))
-        call1 (Vrun_hooks, Qwindow_configuration_change_hook);
+      run_window_configuration_change_hook (XFRAME (WINDOW_FRAME (w)));
     }
 
   unbind_to (count, Qnil);