Re: Testing redisplay code in batch

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Does someone have experience with batch-tests of redisplay code?
> No, but FWIW the subject came up here:
> https://lists.gnu.org/archive/html/emacs-devel/2019-10/msg00971.html

Thanks for digging it up.

Based on the hint from Eli in it, the simple patch below was enough to
make my test "work" in batch mode!

This means: with this patch, the xdisp-tests.el succeeds or not in batch
mode depending on whether the resize_mini_window patch has been applied!

Yay!

WDYT?
Should we add a `internal--force-redisplay-in-initial-terminal` variable
(with a suitable docstring hinting at the fact that setting this to non-nil
 means you'll probably be using code paths that no-one has used before)?


        Stefan


diff --git a/src/dispnew.c b/src/dispnew.c
index d318e26308..4d585bd3e0 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3236,9 +3236,14 @@ update_frame (struct frame *f, bool force_p, bool inhibit_hairy_id_p)
       build_frame_matrix (f);
 
       /* Update the display.  */
-      update_begin (f);
-      paused_p = update_frame_1 (f, force_p, inhibit_hairy_id_p, 1, false);
-      update_end (f);
+      if (FRAME_INITIAL_P (f))
+        paused_p = false;       /* No actual display to update!  */
+      else
+        {
+          update_begin (f);
+          paused_p = update_frame_1 (f, force_p, inhibit_hairy_id_p, 1, false);
+          update_end (f);
+        }
 
       if (FRAME_TERMCAP_P (f) || FRAME_MSDOS_P (f))
         {
diff --git a/src/frame.c b/src/frame.c
index 3f93450437..bf5f6ef910 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -931,18 +931,18 @@ make_frame (bool mini_p)
 
   wset_frame (rw, frame);
 
-  /* 10 is arbitrary,
+  /* 80/40 is arbitrary,
      just so that there is "something there."
      Correct size will be set up later with adjust_frame_size.  */
 
-  SET_FRAME_COLS (f, 10);
-  SET_FRAME_LINES (f, 10);
+  SET_FRAME_COLS (f, 80);
+  SET_FRAME_LINES (f, 40);
   SET_FRAME_WIDTH (f, FRAME_COLS (f) * FRAME_COLUMN_WIDTH (f));
   SET_FRAME_HEIGHT (f, FRAME_LINES (f) * FRAME_LINE_HEIGHT (f));
 
-  rw->total_cols = 10;
+  rw->total_cols = FRAME_COLS (f);
   rw->pixel_width = rw->total_cols * FRAME_COLUMN_WIDTH (f);
-  rw->total_lines = mini_p ? 9 : 10;
+  rw->total_lines = FRAME_LINES (f) - (mini_p ? 1 : 0);
   rw->pixel_height = rw->total_lines * FRAME_LINE_HEIGHT (f);
 
   if (mini_p)
@@ -1101,7 +1101,7 @@ make_initial_frame (void)
 
   terminal = init_initial_terminal ();
 
-  f = make_frame (1);
+  f = make_frame (true);
   XSETFRAME (frame, f);
 
   Vframe_list = Fcons (frame, Vframe_list);
@@ -1136,6 +1136,7 @@ make_initial_frame (void)
     init_frame_faces (f);
 
   last_nonminibuf_frame = f;
+  echo_area_window = f->minibuffer_window;
 
   f->can_set_window_size = true;
   f->after_make_frame = true;
diff --git a/src/xdisp.c b/src/xdisp.c
index 8fadff972f..2505fedbe8 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -11818,7 +11818,7 @@ resize_mini_window (struct window *w, bool exact_p)
 	     don't force w->start to be at the beginning of a screen
 	     line, important parts of the stuff in the mini-window,
 	     such as user prompt, will be hidden from view.  */
-	  move_it_by_lines (&it, 0);
+	  move_it_by_lines (&it, 0); /* bug#43519 */
 	  start = it.current.pos;
 	}
       else
@@ -15414,8 +15414,8 @@ redisplay_internal (void)
   /* No redisplay if running in batch mode or frame is not yet fully
      initialized, or redisplay is explicitly turned off by setting
      Vinhibit_redisplay.  */
-  if (FRAME_INITIAL_P (SELECTED_FRAME ())
-      || !NILP (Vinhibit_redisplay))
+  if (/* FRAME_INITIAL_P (SELECTED_FRAME ())
+       * || */ !NILP (Vinhibit_redisplay))
     return;
 
   /* Don't examine these until after testing Vinhibit_redisplay.
diff --git a/test/src/xdisp-tests.el b/test/src/xdisp-tests.el
index 3d0d0f5830..af46c72398 100644
--- a/test/src/xdisp-tests.el
+++ b/test/src/xdisp-tests.el
@@ -35,17 +35,18 @@ xdisp-tests--minibuffer-resizing
             (let ((ol (make-overlay (point) (point)))
                   (max-mini-window-height 1)
                   (text "askdjfhaklsjdfhlkasjdfhklasdhflkasdhflkajsdhflkashdfkljahsdlfkjahsdlfkjhasldkfhalskdjfhalskdfhlaksdhfklasdhflkasdhflkasdhflkajsdhklajsdgh"))
-             ;; (save-excursion (insert text))
-             ;; (sit-for 2)
-             ;; (delete-region (point) (point-max))
-             (put-text-property 0 1 'cursor t text)
-             (overlay-put ol 'after-string text)
-             (redisplay 'force)
-             (throw 'result
-                    ;; Make sure we do the see "hello" text.
-                    (prog1 (equal (window-start) (point-min))
-                      ;; (list (window-start) (window-end) (window-width))
-                      (delete-overlay ol)))))
+              ;; (save-excursion (insert text))
+              ;; (sit-for 2)
+              ;; (delete-region (point) (point-max))
+              (put-text-property 0 1 'cursor t text)
+              (overlay-put ol 'after-string text)
+              (let ((executing-kbd-macro nil)) ;Don't skip redisplay
+                (redisplay 'force))
+              (throw 'result
+                     ;; Make sure we do the see "hello" text.
+                     (prog1 (equal (window-start) (point-min))
+                       ;; (list (window-start) (window-end) (window-width))
+                       (delete-overlay ol)))))
         (let ((executing-kbd-macro t)) ;Force real minibuffer in `read-string'.
           (read-string "toto: ")))))))