Guile REPL: bug fix: correctly track debugging status

We weren't tracking the "enter debugger" event correctly, and all
evaluations in debug mode were failing.  There's still (at least)
another bug, because error navigation in backtraces seems broken.

2 files changed, 26 insertions, 6 deletions

diff --git a/elisp/geiser-connection.el b/elisp/geiser-connection.el
index d3c99cb..fb16aa6 100644
--- a/elisp/geiser-connection.el
+++ b/elisp/geiser-connection.el
@@ -104,6 +104,7 @@
         (cons :eot (geiser-con--connection-eot-re prompt debug-prompt))
         (cons :prompt prompt)
         (cons :debug-prompt debug-prompt)
+        (cons :is-debugging nil)
         (cons :count 0)
         (cons :completed (make-hash-table :weakness 'value))))
 
@@ -128,6 +129,18 @@
 (defsubst geiser-con--connection-debug-prompt (c)
   (cdr (assoc :debug-prompt c)))
 
+(defsubst geiser-con--connection-is-debugging (c)
+  (cdr (assoc :is-debugging c)))
+
+(defsubst geiser-con--connection-set-debugging (c d)
+  (setcdr (assoc :is-debugging c) d))
+
+(defun geiser-con--connection-update-debugging (c txt)
+  (let* ((dp (geiser-con--connection-debug-prompt c))
+         (is-d (and (stringp dp) (string-match dp txt))))
+    (geiser-con--connection-set-debugging c is-d)
+    is-d))
+
 (defsubst geiser-con--connection-completed (c r)
   (geiser-con--request-deactivate r)
   (puthash (geiser-con--request-id r) r (cdr (assoc :completed c))))
@@ -142,8 +155,8 @@
     new))
 
 (defun geiser-con--has-entered-debugger (con answer)
-  (let ((dp (geiser-con--connection-debug-prompt con)))
-    (and (stringp dp) (string-match dp answer))))
+  (and (not (geiser-con--connection-is-debugging con))
+       (geiser-con--connection-update-debugging con answer)))
 
 (defun geiser-con--connection-close (con)
   (let ((tq (geiser-con--connection-tq con)))
@@ -184,10 +197,10 @@
         `((error (key . geiser-debugger))
           (output . ,answer))
       (condition-case err
-          (let* ((start (and (string-match "((\\(?:result\\|error\\)" answer)
-                             (match-beginning 0)))
-                 (form (car (read-from-string answer start))))
-            (and (listp form) form))
+          (let* ((start (string-match "((\\(?:result\\|error\\) " answer))
+                 (form (or (and start (car (read-from-string answer start)))
+                           `((error . retort-syntax) (output . ,answer)))))
+            form)
         (error `((error (key . geiser-con-error))
                  (output . ,(format "%s\n(%s)"
                                     answer
diff --git a/elisp/geiser-repl.el b/elisp/geiser-repl.el
index cbaaf24..fd274a7 100644
--- a/elisp/geiser-repl.el
+++ b/elisp/geiser-repl.el
@@ -243,6 +243,9 @@ module command as a string")
                                         (geiser-repl--host)
                                         (geiser-repl--port)))))
 
+(defun geiser-repl--update-debugging (txt)
+  (geiser-con--connection-update-debugging geiser-repl--connection txt))
+
 (defun geiser-repl--start-repl (impl address)
   (message "Starting Geiser REPL for %s ..." impl)
   (geiser-repl--to-repl-buffer impl)
@@ -267,6 +270,10 @@ module command as a string")
     (geiser-repl--startup impl address)
     (geiser-repl--autodoc-mode 1)
     (geiser-company--setup geiser-repl-company-p)
+    (add-hook 'comint-output-filter-functions
+              'geiser-repl--update-debugging
+              nil
+              t)
     (message "%s up and running!" (geiser-repl--repl-name impl))))
 
 (defun geiser-repl--start-scheme (impl address prompt)