Fix handling of window-min-height/-width (Bug#16738).

* window.el (window--dump-window, window--dump-frame): New
functions.
(window--min-size-1): Account for window dividers.  When
window-resize-pixelwise is nil, delay rounding till after the
sum of the window components has been calculated.
(window--min-delta-1, window--max-delta-1): When PIXELWISE is
nil make sure at least one text line and two text columns remain
fully visible.
(window-resize): Signal an error when window-resize-apply fails.
(window--resize-child-windows): Fix calculation of by how many
pixels a window can still be shrunk via window-new-normal.
(adjust-window-trailing-edge): Call window--resizable with
correct TRAIL argument.

4 files changed, 158 insertions, 53 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 7eb88ebd968..51c52be172f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,20 @@
+2014-02-21  Martin Rudalics  <rudalics@gmx.at>
+
+        Fix handling of window-min-height/-width (Bug#16738).
+        * window.el (window--dump-window, window--dump-frame): New
+        functions.
+        (window--min-size-1): Account for window dividers.  When
+        window-resize-pixelwise is nil, delay rounding till after the
+        sum of the window components has been calculated.
+        (window--min-delta-1, window--max-delta-1): When PIXELWISE is
+        nil make sure at least one text line and two text columns remain
+        fully visible.
+        (window-resize): Signal an error when window-resize-apply fails.
+        (window--resize-child-windows): Fix calculation of by how many
+        pixels a window can still be shrunk via window-new-normal.
+        (adjust-window-trailing-edge): Call window--resizable with
+        correct TRAIL argument.
+
 2014-02-21  Michael Albinus  <michael.albinus@gmx.de>
 
         * net/tramp.el (tramp-check-cached-permissions):
diff --git a/lisp/window.el b/lisp/window.el
index c4854f02399..357d49d02a2 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -1012,6 +1012,84 @@ FRAME defaults to the selected frame."
   (window--side-check frame)
   (window--atom-check frame))
 
+;; Dumping frame/window contents.
+(defun window--dump-window (&optional window erase)
+  "Dump WINDOW to buffer *window-frame-dump*.
+WINDOW must be a valid window and defaults to the selected one.
+Optional argument ERASE non-nil means erase *window-frame-dump*
+before writing to it."
+  (setq window (window-normalize-window window))
+  (with-current-buffer (get-buffer-create "*window-frame-dump*")
+    (when erase (erase-buffer))
+    (insert
+     (format "%s   parent: %s\n" window (window-parent window))
+     (format "pixel left: %s   top: %s   size: %s x %s   new: %s\n"
+             (window-pixel-left window) (window-pixel-top window)
+             (window-size window t t) (window-size window nil t)
+             (window-new-pixel window))
+     (format "char left: %s   top: %s   size: %s x %s   new: %s\n"
+             (window-left-column window) (window-top-line window)
+             (window-total-size window t) (window-total-size window)
+             (window-new-total window))
+     (format "normal: %s x %s   new: %s\n"
+             (window-normal-size window t) (window-normal-size window)
+             (window-new-normal window)))
+    (when (window-live-p window)
+      (let ((fringes (window-fringes window))
+            (margins (window-margins window)))
+        (insert
+         (format "body pixel: %s x %s   char: %s x %s\n"
+                 (window-body-width window t) (window-body-height window t)
+                 (window-body-width window) (window-body-height window))
+         (format "width left fringe: %s  left margin: %s  right margin: %s\n"
+                 (car fringes) (or (car margins) 0) (or (cdr margins) 0))
+         (format "width right fringe: %s  scroll-bar: %s  divider: %s\n"
+                 (cadr fringes)
+                 (window-scroll-bar-width window)
+                 (window-right-divider-width window))
+         (format "height header-line: %s  mode-line: %s  divider: %s\n"
+                 (window-header-line-height window)
+                 (window-mode-line-height window)
+                 (window-bottom-divider-width window)))))
+    (insert "\n")))
+
+(defun window--dump-frame (&optional window-or-frame)
+  "Dump WINDOW-OR-FRAME to buffer *window-frame-dump*.
+WINDOW-OR-FRAME can be a frame or a window and defaults to the
+selected frame.  When WINDOW-OR-FRAME is a window, dump that
+window's frame.  The buffer *window-frame-dump* is erased before
+dumping to it."
+  (interactive)
+  (let* ((window
+          (cond
+           ((or (not window-or-frame)
+                (frame-live-p window-or-frame))
+            (frame-root-window window-or-frame))
+           ((or (window-live-p window-or-frame)
+                (window-child window-or-frame))
+            window-or-frame)
+           (t
+            (frame-root-window))))
+         (frame (window-frame window)))
+    (with-current-buffer (get-buffer-create "*window-frame-dump*")
+      (erase-buffer)
+      (insert
+       (format "frame pixel: %s x %s   cols/lines: %s x %s   units: %s x %s\n"
+               (frame-pixel-width frame) (frame-pixel-height frame)
+               (frame-total-cols frame) (frame-text-lines frame) ; (frame-total-lines frame)
+               (frame-char-width frame) (frame-char-height frame))
+       (format "frame text pixel: %s x %s   cols/lines: %s x %s\n"
+               (frame-text-width frame) (frame-text-height frame)
+               (frame-text-cols frame) (frame-text-lines frame))
+       (format "tool: %s  scroll: %s  fringe: %s  border: %s  right: %s  bottom: %s\n\n"
+               (tool-bar-height frame t)
+               (frame-scroll-bar-width frame)
+               (frame-fringe-width frame)
+               (frame-border-width frame)
+               (frame-right-divider-width frame)
+               (frame-bottom-divider-width frame)))
+      (walk-window-tree 'window--dump-window frame t t))))
+
 ;;; Window sizes.
 (defun window-total-size (&optional window horizontal round)
   "Return the total height or width of WINDOW.
@@ -1140,55 +1218,46 @@ of WINDOW."
           ;; windows such that the new (or resized) windows can get a
           ;; size less than the user-specified `window-min-height' and
           ;; `window-min-width'.
-          (let ((frame (window-frame window))
-                (fringes (window-fringes window))
-                (scroll-bars (window-scroll-bars window)))
+          (let* ((char-size (frame-char-size window t))
+                 (fringes (window-fringes window))
+                 (pixel-width
+                  (+ (window-safe-min-size window t t)
+                     (car fringes) (cadr fringes)
+                     (window-scroll-bar-width window)
+                     (window-right-divider-width window))))
             (if pixelwise
                 (max
-                 (+ (window-safe-min-size window t t)
-                    (car fringes) (cadr fringes)
-                    (cond
-                     ((memq (nth 2 scroll-bars) '(left right))
-                      (nth 1 scroll-bars))
-                     ((memq (frame-parameter frame 'vertical-scroll-bars)
-                            '(left right))
-                      (frame-parameter frame 'scroll-bar-width))
-                     (t 0)))
+                 (if window-resize-pixelwise
+                     pixel-width
+                   ;; Round up to next integral of columns.
+                   (* (ceiling pixel-width char-size) char-size))
                  (if (window--size-ignore-p window ignore)
                      0
                    (window-min-pixel-width)))
               (max
-               (+ window-safe-min-width
-                  (ceiling (car fringes) (frame-char-width frame))
-                  (ceiling (cadr fringes) (frame-char-width frame))
-                  (cond
-                   ((memq (nth 2 scroll-bars) '(left right))
-                    (nth 1 scroll-bars))
-                 ((memq (frame-parameter frame 'vertical-scroll-bars)
-                        '(left right))
-                  (ceiling (or (frame-parameter frame 'scroll-bar-width) 14)
-                           (frame-char-width)))
-                 (t 0)))
+               (ceiling pixel-width char-size)
                (if (window--size-ignore-p window ignore)
                    0
                  window-min-width)))))
-         (pixelwise
-          (max
-           (+ (window-safe-min-size window nil t)
-              (window-header-line-height window)
-              (window-mode-line-height window))
-           (if (window--size-ignore-p window ignore)
-               0
-             (window-min-pixel-height))))
-         (t
-          ;; For the minimum height of a window take any mode- or
-          ;; header-line into account.
-          (max (+ window-safe-min-height
-                  (if header-line-format 1 0)
-                  (if mode-line-format 1 0))
-               (if (window--size-ignore-p window ignore)
-                   0
-                 window-min-height))))))))
+         ((let ((char-size (frame-char-size window))
+                (pixel-height
+                 (+ (window-safe-min-size window nil t)
+                    (window-header-line-height window)
+                    (window-mode-line-height window)
+                    (window-bottom-divider-width window))))
+            (if pixelwise
+                (max
+                 (if window-resize-pixelwise
+                     pixel-height
+                   ;; Round up to next integral of lines.
+                   (* (ceiling pixel-height char-size) char-size))
+                 (if (window--size-ignore-p window ignore)
+                     0
+                   (window-min-pixel-height)))
+              (max (ceiling pixel-height char-size)
+                   (if (window--size-ignore-p window ignore)
+                       0
+                     window-min-height))))))))))
 
 (defun window-sizable (window delta &optional horizontal ignore pixelwise)
   "Return DELTA if DELTA lines can be added to WINDOW.
@@ -1323,9 +1392,10 @@ WINDOW can be resized in the desired direction.  The function
             (unless (eq sub window)
               (setq delta
                     (min delta
-                         (- (window-size sub horizontal pixelwise 'floor)
-                            (window-min-size
-                             sub horizontal ignore pixelwise)))))
+                         (max (- (window-size sub horizontal pixelwise 'ceiling)
+                                 (window-min-size
+                                  sub horizontal ignore pixelwise))
+                              0))))
             (setq sub (window-right sub))))
         (if noup
             delta
@@ -1400,9 +1470,11 @@ by which WINDOW can be shrunk."
                  (t
                   (setq delta
                         (+ delta
-                           (- (window-size sub horizontal pixelwise 'floor)
-                              (window-min-size
-                               sub horizontal ignore pixelwise))))))
+                           (max
+                            (- (window-size sub horizontal pixelwise 'ceiling)
+                               (window-min-size
+                                sub horizontal ignore pixelwise))
+                            0)))))
                 (setq sub (window-right sub))))
           ;; For an ortho-combination throw DELTA when at least one
           ;; child window is fixed-size.
@@ -2317,9 +2389,11 @@ instead."
         ;; Otherwise, resize all other windows in the same combination.
         (window--resize-siblings window delta horizontal ignore))
       (when (window--resize-apply-p frame horizontal)
-        (window-resize-apply frame horizontal)
-        (window--pixel-to-total frame horizontal)
-        (run-window-configuration-change-hook frame)))
+        (if (window-resize-apply frame horizontal)
+            (progn
+              (window--pixel-to-total frame horizontal)
+              (run-window-configuration-change-hook frame))
+          (error "Failed to apply resizing %s" window))))
      (t
       (error "Cannot resize window %s" window)))))
 
@@ -2560,7 +2634,7 @@ already set by this routine."
           (setq best-value most-negative-fixnum)
           (while sub
             (when (and (consp (window-new-normal sub))
-                       (not (zerop (car (window-new-normal sub))))
+                       (not (<= (car (window-new-normal sub)) 0))
                        (> (cdr (window-new-normal sub)) best-value))
               (setq best-window sub)
               (setq best-value (cdr (window-new-normal sub))))
@@ -2576,7 +2650,7 @@ already set by this routine."
              best-window
              (if (= (car (window-new-normal best-window)) best-delta)
                  'skip      ; We can't shrink best-window any further.
-               (cons (1- (car (window-new-normal best-window)))
+               (cons (- (car (window-new-normal best-window)) best-delta)
                      (- (/ (float (window-new-pixel best-window))
                            parent-total)
                         (window-normal-size best-window horizontal))))))))
@@ -2941,7 +3015,7 @@ move it as far as possible in the desired direction."
           (window--resize-reset frame horizontal)
           ;; Try to enlarge LEFT first.
           (setq this-delta (window--resizable
-                            left delta horizontal nil nil nil nil pixelwise))
+                            left delta horizontal nil 'after nil nil pixelwise))
           (unless (zerop this-delta)
             (window--resize-this-window
              left this-delta horizontal nil t 'before
@@ -2970,7 +3044,7 @@ move it as far as possible in the desired direction."
           ;; Try to enlarge RIGHT.
           (setq this-delta
                 (window--resizable
-                 right (- delta) horizontal nil nil nil nil pixelwise))
+                 right (- delta) horizontal nil 'before nil nil pixelwise))
           (unless (zerop this-delta)
             (window--resize-this-window
              right this-delta horizontal nil t 'after
diff --git a/src/ChangeLog b/src/ChangeLog
index ae35ff6cce2..2b631dfc5f9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2014-02-21  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.c (Fwindow_scroll_bar_width): New function.
+
 2014-02-21  Paul Eggert  <eggert@cs.ucla.edu>
 
         Pacify GCC when configuring with --enable-gcc-warnings.
diff --git a/src/window.c b/src/window.c
index b2c97d52157..0f62838d672 100644
--- a/src/window.c
+++ b/src/window.c
@@ -974,6 +974,15 @@ WINDOW must be a live window and defaults to the selected one.  */)
   return (make_number (WINDOW_BOTTOM_DIVIDER_WIDTH (decode_live_window (window))));
 }
 
+DEFUN ("window-scroll-bar-width", Fwindow_scroll_bar_width,
+       Swindow_scroll_bar_width, 0, 1, 0,
+       doc: /* Return the width in pixels of WINDOW's vertical scrollbar.
+WINDOW must be a live window and defaults to the selected one.  */)
+  (Lisp_Object window)
+{
+  return (make_number (WINDOW_SCROLL_BAR_AREA_WIDTH (decode_live_window (window))));
+}
+
 DEFUN ("window-hscroll", Fwindow_hscroll, Swindow_hscroll, 0, 1, 0,
        doc: /* Return the number of columns by which WINDOW is scrolled from left margin.
 WINDOW must be a live window and defaults to the selected one.  */)
@@ -7363,6 +7372,7 @@ pixelwise even if this option is nil.  */);
   defsubr (&Swindow_header_line_height);
   defsubr (&Swindow_right_divider_width);
   defsubr (&Swindow_bottom_divider_width);
+  defsubr (&Swindow_scroll_bar_width);
   defsubr (&Swindow_inside_edges);
   defsubr (&Swindow_inside_pixel_edges);
   defsubr (&Swindow_inside_absolute_pixel_edges);