From 7bc1af89c80dbb9093e28d3fe7c525e369543dd6 Mon Sep 17 00:00:00 2001
From: dybvig <dyb@scheme.com>
Date: Sun, 21 Aug 2016 10:54:26 -0400
Subject: [PATCH] - instead of default-exception handler, new-cafe establishes
 a handler   that calls the current value of base-exception-handler so the
 handler   can be overridden, as we do in our own make files.     cafe.ss,    
 7.ms

original commit: 99b763e30d22b205106ef9a84ea2e0a928fd0b30
---
 LOG       |  5 +++++
 mats/7.ms | 19 +++++++++++++++++++
 s/cafe.ss |  3 ++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/LOG b/LOG
index ffcdf6e7cf..9437c7ac66 100644
--- a/LOG
+++ b/LOG
@@ -291,3 +291,8 @@
   not-like patterns.
     cp0.ss,
     cp0.ms, 4.ms
+- instead of default-exception handler, new-cafe establishes a handler
+  that calls the current value of base-exception-handler so the handler
+  can be overridden, as we do in our own make files.
+    cafe.ss,
+    7.ms
diff --git a/mats/7.ms b/mats/7.ms
index 21ea012a2f..6d09c78b23 100644
--- a/mats/7.ms
+++ b/mats/7.ms
@@ -3300,6 +3300,25 @@ evaluating module init
              (new-cafe))
            (get))))
      "Huh? \nException: invalid syntax (if)\nHuh? \n")
+   (equal?
+     (separate-eval
+       `(let ([ip (open-string-input-port "
+                    (base-exception-handler
+                      (lambda (c)
+                        (fprintf (console-output-port) \"~%>>> \")
+                        (display-condition c (console-output-port))
+                        (fprintf (console-output-port) \" <<<~%\")
+                        (reset)))
+                    (if)")])
+          (let-values ([(op get) (open-string-output-port)])
+            (parameterize ([console-input-port ip]
+                           [console-output-port op]
+                           [console-error-port op]
+                           [#%$cafe 0]
+                           [waiter-prompt-string "Huh?"])
+              (new-cafe))
+            (get))))
+     "\"Huh? Huh? \\n>>> Exception: invalid syntax (if) <<<\\nHuh? \\n\"\n")
  )
 
 (mat reset
diff --git a/s/cafe.ss b/s/cafe.ss
index 74cdb4c6f5..8f928f68fb 100644
--- a/s/cafe.ss
+++ b/s/cafe.ss
@@ -209,7 +209,8 @@ Type e to exit interrupt handler and continue
                  (reset-handler (lambda () (k2)))
                  (call/cc (lambda (k) (set! k2 k)))
                  (parameterize ([$cafe (+ ($cafe) 1)] [$interrupt reset])
-                   (with-exception-handler default-exception-handler
+                   (with-exception-handler
+                     (lambda (c) ((base-exception-handler) c))
                      (lambda ()
                        (waiter ($cafe) eval))))))))]))))
 )