(gud-filter): Save up text that arrives while processing previous text.

1 files changed, 44 insertions, 20 deletions

diff --git a/lisp/gud.el b/lisp/gud.el
index 87917045838..787d7e74bc2 100644
--- a/lisp/gud.el
+++ b/lisp/gud.el
@@ -1175,6 +1175,13 @@ comint mode, which see."
   (cond ((eq major-mode 'gud-mode)
         (setq gud-comint-buffer (current-buffer)))))
 
+(defvar gud-filter-defer-flag nil
+  "Non-nil means don't process anything from the debugger right now.
+It is saved for when this flag is not set.")
+
+(defvar gud-filter-pending-text nil
+  "Non-nil means this is text that has been saved for later in `gud-filter'.")
+
 ;; These functions are responsible for inserting output from your debugger
 ;; into the buffer.  The hard work is done by the method that is
 ;; the value of gud-marker-filter.
@@ -1183,26 +1190,43 @@ comint mode, which see."
   ;; Here's where the actual buffer insertion is done
   (let (output)
     (if (buffer-name (process-buffer proc))
-        (save-excursion
-          (set-buffer (process-buffer proc))
-          ;; If we have been so requested, delete the debugger prompt.
-          (if (marker-buffer gud-delete-prompt-marker)
-              (progn
-                (delete-region (process-mark proc) gud-delete-prompt-marker)
-                (set-marker gud-delete-prompt-marker nil)))
-          ;; Save the process output, checking for source file markers.
-          (setq output (gud-marker-filter string))
-          ;; Check for a filename-and-line number.
-          ;; Don't display the specified file
-          ;; unless (1) point is at or after the position where output appears
-          ;; and (2) this buffer is on the screen.
-          (if (and gud-last-frame
-                   (>= (point) (process-mark proc))
-                   (get-buffer-window (current-buffer)))
-              (gud-display-frame))
-          ;; Let the comint filter do the actual insertion.
-          ;; That lets us inherit various comint features.
-          (comint-output-filter proc output)))))
+        (if gud-filter-defer-flag
+            ;; If we can't process any text now,
+            ;; save it for later.
+            (setq gud-filter-pending-text
+                  (concat (or gud-filter-pending-text "") string))
+          (save-excursion
+            ;; If we have to ask a question during the processing,
+            ;; defer any additional text that comes from the debugger
+            ;; during that time.
+            (let ((gud-filter-defer-flag t))
+              ;; Process now any text we previously saved up.
+              (if gud-filter-pending-text
+                  (setq string (concat gud-filter-pending-text string)
+                        gud-filter-pending-text nil))
+              (set-buffer (process-buffer proc))
+              ;; If we have been so requested, delete the debugger prompt.
+              (if (marker-buffer gud-delete-prompt-marker)
+                  (progn
+                    (delete-region (process-mark proc) gud-delete-prompt-marker)
+                    (set-marker gud-delete-prompt-marker nil)))
+              ;; Save the process output, checking for source file markers.
+              (setq output (gud-marker-filter string))
+              ;; Check for a filename-and-line number.
+              ;; Don't display the specified file
+              ;; unless (1) point is at or after the position where output appears
+              ;; and (2) this buffer is on the screen.
+              (if (and gud-last-frame
+                       (>= (point) (process-mark proc))
+                       (get-buffer-window (current-buffer)))
+                  (gud-display-frame))
+              ;; Let the comint filter do the actual insertion.
+              ;; That lets us inherit various comint features.
+              (comint-output-filter proc output))
+            ;; If we deferred text that arrived during this processing,
+            ;; handle it now.
+            (if gud-filter-pending-text
+                (gud-filter proc "")))))))
 
 (defun gud-sentinel (proc msg)
   (cond ((null (buffer-name (process-buffer proc)))