* lisp/emacs-lisp/debug.el (debug): Merge the non-interactive cases

bug#38927

(cherry picked from commit 5020594)

Author: doublep

lisp/emacs-lisp/debug.el

@@ -168,158 +168,150 @@ first will be printed into the backtrace buffer.
 If `inhibit-redisplay' is non-nil when this function is called,
 the debugger will not be entered."
   (interactive)
-  (cond
-   (inhibit-redisplay
-    ;; Don't really try to enter debugger within an eval from redisplay.
-    debugger-value)
-   ((and (eq t (framep (selected-frame)))
-         (equal "initial_terminal" (terminal-name)))
-    ;; We're in the initial-frame (where `message' just outputs to stdout) so
-    ;; there's no tty or GUI frame to display the backtrace and interact with
-    ;; it: just dump a backtrace to stdout.
-    ;; This happens for example while handling an error in code from
-    ;; early-init.el with --debug-init.
-    (message "Error: %S" args)
-    (let ((print-escape-newlines t)
-          (print-escape-control-characters t)
-          (print-level 8)
-          (print-length 50)
-          (skip t))             ;Skip the first frame (i.e. the `debug' frame)!
-      (mapbacktrace (lambda (_evald func args _flags)
-                      (if skip
-                          (setq skip nil)
-                        (message "  %S" (cons func args))))
-                    'debug)))
-   (t
-    (unless noninteractive
-      (message "Entering debugger..."))
-    (let (debugger-value
-	  (debugger-previous-state
-           (if (get-buffer "*Backtrace*")
-               (with-current-buffer (get-buffer "*Backtrace*")
-                 (debugger--save-buffer-state))))
-          (debugger-args args)
-	  (debugger-buffer (get-buffer-create "*Backtrace*"))
-	  (debugger-old-buffer (current-buffer))
-	  (debugger-window nil)
-	  (debugger-step-after-exit nil)
-          (debugger-will-be-back nil)
-	  ;; Don't keep reading from an executing kbd macro!
-	  (executing-kbd-macro nil)
-	  ;; Save the outer values of these vars for the `e' command
-	  ;; before we replace the values.
-	  (debugger-outer-match-data (match-data))
-	  (debugger-with-timeout-suspend (with-timeout-suspend)))
-      ;; Set this instead of binding it, so that `q'
-      ;; will not restore it.
-      (setq overriding-terminal-local-map nil)
-      ;; Don't let these magic variables affect the debugger itself.
-      (let ((last-command nil) this-command track-mouse
-	    (inhibit-trace t)
-	    unread-command-events
-	    unread-post-input-method-events
-	    last-input-event last-command-event last-nonmenu-event
-	    last-event-frame
-	    overriding-local-map
-	    load-read-function
-	    ;; If we are inside a minibuffer, allow nesting
-	    ;; so that we don't get an error from the `e' command.
-	    (enable-recursive-minibuffers
-	     (or enable-recursive-minibuffers (> (minibuffer-depth) 0)))
-	    (standard-input t) (standard-output t)
-	    inhibit-redisplay
-	    (cursor-in-echo-area nil)
-	    (window-configuration (current-window-configuration)))
-	(unwind-protect
-	    (save-excursion
-	      (when (eq (car debugger-args) 'debug)
-		;; Skip the frames for backtrace-debug, byte-code,
-		;; debug--implement-debug-on-entry and the advice's `apply'.
-		(backtrace-debug 4 t)
-		;; Place an extra debug-on-exit for macro's.
-		(when (eq 'lambda (car-safe (cadr (backtrace-frame 4))))
-		  (backtrace-debug 5 t)))
-              (with-current-buffer debugger-buffer
-                (unless (derived-mode-p 'debugger-mode)
-	          (debugger-mode))
-	        (debugger-setup-buffer debugger-args)
-	        (when noninteractive
-		  ;; If the backtrace is long, save the beginning
-		  ;; and the end, but discard the middle.
-		  (when (> (count-lines (point-min) (point-max))
-			   debugger-batch-max-lines)
-		    (goto-char (point-min))
-		    (forward-line (/ 2 debugger-batch-max-lines))
-		    (let ((middlestart (point)))
-		      (goto-char (point-max))
-		      (forward-line (- (/ 2 debugger-batch-max-lines)
-				       debugger-batch-max-lines))
-		      (delete-region middlestart (point)))
-		    (insert "...\n"))
-		  (goto-char (point-min))
-		  (message "%s" (buffer-string))
-		  (kill-emacs -1)))
-	      (pop-to-buffer
-	       debugger-buffer
-	       `((display-buffer-reuse-window
-		  display-buffer-in-previous-window
-		  display-buffer-below-selected)
-		 . ((window-min-height . 10)
-                    (window-height . fit-window-to-buffer)
-		    ,@(when (and (window-live-p debugger-previous-window)
-				 (frame-visible-p
-				  (window-frame debugger-previous-window)))
-		        `((previous-window . ,debugger-previous-window))))))
-	      (setq debugger-window (selected-window))
-	      (if (eq debugger-previous-window debugger-window)
-		  (when debugger-jumping-flag
-		    ;; Try to restore previous height of debugger
-		    ;; window.
-		    (condition-case nil
-			(window-resize
-			 debugger-window
-			 (- debugger-previous-window-height
-			    (window-total-height debugger-window)))
-		      (error nil)))
-		(setq debugger-previous-window debugger-window))
-	      (message "")
-	      (let ((standard-output nil)
-		    (buffer-read-only t))
-		(message "")
-		;; Make sure we unbind buffer-read-only in the right buffer.
-		(save-excursion
-		  (recursive-edit))))
-	  (when (and (window-live-p debugger-window)
-		     (eq (window-buffer debugger-window) debugger-buffer))
-	    ;; Record height of debugger window.
-	    (setq debugger-previous-window-height
-		  (window-total-height debugger-window)))
-	  (if debugger-will-be-back
-	      ;; Restore previous window configuration (Bug#12623).
-	      (set-window-configuration window-configuration)
+  (if inhibit-redisplay
+      ;; Don't really try to enter debugger within an eval from redisplay.
+      debugger-value
+    (let ((non-interactive-frame
+           (or noninteractive           ;FIXME: Presumably redundant.
+               ;; If we're in the initial-frame (where `message' just
+               ;; outputs to stdout) so there's no tty or GUI frame to
+               ;; display the backtrace and interact with it: just dump a
+               ;; backtrace to stdout.  This happens for example while
+               ;; handling an error in code from early-init.el with
+               ;; --debug-init.
+               (and (eq t (framep (selected-frame)))
+                    (equal "initial_terminal" (terminal-name)))))
+          ;; Don't let `inhibit-message' get in our way (especially important if
+          ;; `non-interactive-frame' evaluated to a non-nil value.
+          (inhibit-message nil))
+      (unless non-interactive-frame
+        (message "Entering debugger..."))
+      (let (debugger-value
+	    (debugger-previous-state
+             (if (get-buffer "*Backtrace*")
+                 (with-current-buffer (get-buffer "*Backtrace*")
+                   (debugger--save-buffer-state))))
+            (debugger-args args)
+	    (debugger-buffer (get-buffer-create "*Backtrace*"))
+	    (debugger-old-buffer (current-buffer))
+	    (debugger-window nil)
+	    (debugger-step-after-exit nil)
+            (debugger-will-be-back nil)
+	    ;; Don't keep reading from an executing kbd macro!
+	    (executing-kbd-macro nil)
+	    ;; Save the outer values of these vars for the `e' command
+	    ;; before we replace the values.
+	    (debugger-outer-match-data (match-data))
+	    (debugger-with-timeout-suspend (with-timeout-suspend)))
+        ;; Set this instead of binding it, so that `q'
+        ;; will not restore it.
+        (setq overriding-terminal-local-map nil)
+        ;; Don't let these magic variables affect the debugger itself.
+        (let ((last-command nil) this-command track-mouse
+	      (inhibit-trace t)
+	      unread-command-events
+	      unread-post-input-method-events
+	      last-input-event last-command-event last-nonmenu-event
+	      last-event-frame
+	      overriding-local-map
+	      load-read-function
+	      ;; If we are inside a minibuffer, allow nesting
+	      ;; so that we don't get an error from the `e' command.
+	      (enable-recursive-minibuffers
+	       (or enable-recursive-minibuffers (> (minibuffer-depth) 0)))
+	      (standard-input t) (standard-output t)
+	      inhibit-redisplay
+	      (cursor-in-echo-area nil)
+	      (window-configuration (current-window-configuration)))
+	  (unwind-protect
+	      (save-excursion
+	        (when (eq (car debugger-args) 'debug)
+		  ;; Skip the frames for backtrace-debug, byte-code,
+		  ;; debug--implement-debug-on-entry and the advice's `apply'.
+		  (backtrace-debug 4 t)
+		  ;; Place an extra debug-on-exit for macro's.
+		  (when (eq 'lambda (car-safe (cadr (backtrace-frame 4))))
+		    (backtrace-debug 5 t)))
+                (with-current-buffer debugger-buffer
+                  (unless (derived-mode-p 'debugger-mode)
+	            (debugger-mode))
+	          (debugger-setup-buffer debugger-args)
+	          (when non-interactive-frame
+		    ;; If the backtrace is long, save the beginning
+		    ;; and the end, but discard the middle.
+                    (let ((inhibit-read-only t))
+		      (when (> (count-lines (point-min) (point-max))
+			       debugger-batch-max-lines)
+		        (goto-char (point-min))
+		        (forward-line (/ debugger-batch-max-lines 2))
+		        (let ((middlestart (point)))
+		          (goto-char (point-max))
+		          (forward-line (- (/ debugger-batch-max-lines 2)))
+		          (delete-region middlestart (point)))
+		        (insert "...\n")))
+		    (message "%s" (buffer-string))
+		    (kill-emacs -1)))
+	        (pop-to-buffer
+	         debugger-buffer
+	         `((display-buffer-reuse-window
+		    display-buffer-in-previous-window
+		    display-buffer-below-selected)
+		   . ((window-min-height . 10)
+                      (window-height . fit-window-to-buffer)
+		      ,@(when (and (window-live-p debugger-previous-window)
+				   (frame-visible-p
+				    (window-frame debugger-previous-window)))
+		          `((previous-window . ,debugger-previous-window))))))
+	        (setq debugger-window (selected-window))
+	        (if (eq debugger-previous-window debugger-window)
+		    (when debugger-jumping-flag
+		      ;; Try to restore previous height of debugger
+		      ;; window.
+		      (condition-case nil
+			  (window-resize
+			   debugger-window
+			   (- debugger-previous-window-height
+			      (window-total-height debugger-window)))
+		        (error nil)))
+		  (setq debugger-previous-window debugger-window))
+	        (message "")
+	        (let ((standard-output nil)
+		      (buffer-read-only t))
+		  (message "")
+		  ;; Make sure we unbind buffer-read-only in the right buffer.
+		  (save-excursion
+		    (recursive-edit))))
 	    (when (and (window-live-p debugger-window)
 		       (eq (window-buffer debugger-window) debugger-buffer))
-	      (progn
-		;; Unshow debugger-buffer.
-		(quit-restore-window debugger-window debugger-bury-or-kill)
-		;; Restore current buffer (Bug#12502).
-		(set-buffer debugger-old-buffer)))
-            ;; Forget debugger window, it won't be back (Bug#17882).
-            (setq debugger-previous-window nil))
-          ;; Restore previous state of debugger-buffer in case we were
-          ;; in a recursive invocation of the debugger, otherwise just
-          ;; erase the buffer.
-	  (when (buffer-live-p debugger-buffer)
-	    (with-current-buffer debugger-buffer
-	      (if debugger-previous-state
-                  (debugger--restore-buffer-state debugger-previous-state)
-                (setq backtrace-insert-header-function nil)
-                (setq backtrace-frames nil)
-                (backtrace-print))))
-	  (with-timeout-unsuspend debugger-with-timeout-suspend)
-	  (set-match-data debugger-outer-match-data)))
-      (setq debug-on-next-call debugger-step-after-exit)
-      debugger-value))))
+	      ;; Record height of debugger window.
+	      (setq debugger-previous-window-height
+		    (window-total-height debugger-window)))
+	    (if debugger-will-be-back
+	        ;; Restore previous window configuration (Bug#12623).
+	        (set-window-configuration window-configuration)
+	      (when (and (window-live-p debugger-window)
+		         (eq (window-buffer debugger-window) debugger-buffer))
+	        (progn
+		  ;; Unshow debugger-buffer.
+		  (quit-restore-window debugger-window debugger-bury-or-kill)
+		  ;; Restore current buffer (Bug#12502).
+		  (set-buffer debugger-old-buffer)))
+              ;; Forget debugger window, it won't be back (Bug#17882).
+              (setq debugger-previous-window nil))
+            ;; Restore previous state of debugger-buffer in case we were
+            ;; in a recursive invocation of the debugger, otherwise just
+            ;; erase the buffer.
+	    (when (buffer-live-p debugger-buffer)
+	      (with-current-buffer debugger-buffer
+	        (if debugger-previous-state
+                    (debugger--restore-buffer-state debugger-previous-state)
+                  (setq backtrace-insert-header-function nil)
+                  (setq backtrace-frames nil)
+                  (backtrace-print))))
+	    (with-timeout-unsuspend debugger-with-timeout-suspend)
+	    (set-match-data debugger-outer-match-data)))
+        (setq debug-on-next-call debugger-step-after-exit)
+        debugger-value))))
 
 (defun debugger--print (obj &optional stream)
   (condition-case err