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commit 707d9803c6eeaa3542e2459cc2cf47370f007440
parent 5d6b4317d8f87874a098b8e5e1c513e68d7b40f3
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Mon, 17 Aug 2026 17:00:26 +0200

fix helper cleanup on signal

Diffstat:
M
src/mhd/mhd_typst.c
 | 
64
+++++++++++++++++++++++++++++++++++++++++++++++++---------------

1 file changed, 49 insertions(+), 15 deletions(-)
diff --git a/src/mhd/mhd_typst.c b/src/mhd/mhd_typst.c
@@ -362,11 +362,17 @@ pdftk_done_cb (void *cls,
   case GNUNET_OS_PROCESS_RUNNING:
     /* we should not get this notification */
     GNUNET_break (0);
-    return;
+    typst_context_fail (tc,
+                        TALER_EC_EXCHANGE_GENERIC_PDFTK_CRASH,
+                        "pdftk in unexpected state");
+    break;
   case GNUNET_OS_PROCESS_STOPPED:
     /* Someone is SIGSTOPing our helper!? */
     GNUNET_break (0);
-    return;
+    typst_context_fail (tc,
+                        TALER_EC_EXCHANGE_GENERIC_PDFTK_CRASH,
+                        "pdftk was stopped");
+    break;
   case GNUNET_OS_PROCESS_EXITED:
     if (0 != exit_code)
     {
@@ -459,6 +465,33 @@ cancel_async (void *cls)
 
 
 /**
+ * Fail the typst context @a tc and clean it up asynchronously.
+ *
+ * Note that several stages may fail within the same SIGCHLD batch, in
+ * which case the clean-up task will already have been scheduled by the
+ * first failure; we must not schedule it a second time (and must not
+ * clean up synchronously, as we are called from the child-death
+ * notification).
+ *
+ * @param[in,out] tc context to fail
+ * @param ec error code to return to the client
+ * @param hint hint text to return to the client
+ */
+static void
+stage_fail (struct TALER_MHD_TypstContext *tc,
+            enum TALER_ErrorCode ec,
+            const char *hint)
+{
+  typst_context_fail (tc,
+                      ec,
+                      hint);
+  if (NULL == tc->t)
+    tc->t = GNUNET_SCHEDULER_add_now (&cancel_async,
+                                      tc);
+}
+
+
+/**
  * Called when a typst helper exited.
  *
  * @param cls our `struct TypstStage *`
@@ -484,10 +517,16 @@ typst_done_cb (void *cls,
   case GNUNET_OS_PROCESS_RUNNING:
     /* we should not get this notification */
     GNUNET_break (0);
+    stage_fail (tc,
+                TALER_EC_EXCHANGE_GENERIC_TYPST_CRASH,
+                "Typst in unexpected state");
     return;
   case GNUNET_OS_PROCESS_STOPPED:
     /* Someone is SIGSTOPing our helper!? */
     GNUNET_break (0);
+    stage_fail (tc,
+                TALER_EC_EXCHANGE_GENERIC_TYPST_CRASH,
+                "Typst was stopped");
     return;
   case GNUNET_OS_PROCESS_EXITED:
     if (0 != exit_code)
@@ -501,12 +540,9 @@ typst_done_cb (void *cls,
                        sizeof (err),
                        "Typst exited with status %d",
                        (int) exit_code);
-      typst_context_fail (tc,
-                          TALER_EC_EXCHANGE_GENERIC_TYPST_TEMPLATE_FAILURE,
-                          err);
-      GNUNET_assert (NULL == tc->t);
-      tc->t = GNUNET_SCHEDULER_add_now (&cancel_async,
-                                        tc);
+      stage_fail (tc,
+                  TALER_EC_EXCHANGE_GENERIC_TYPST_TEMPLATE_FAILURE,
+                  err);
       return;
     }
     break;
@@ -521,12 +557,9 @@ typst_done_cb (void *cls,
                        sizeof (err),
                        "Typst died with signal %d",
                        (int) exit_code);
-      typst_context_fail (tc,
-                          TALER_EC_EXCHANGE_GENERIC_TYPST_CRASH,
-                          err);
-      GNUNET_assert (NULL == tc->t);
-      tc->t = GNUNET_SCHEDULER_add_now (&cancel_async,
-                                        tc);
+      stage_fail (tc,
+                  TALER_EC_EXCHANGE_GENERIC_TYPST_CRASH,
+                  err);
       return;
     }
     break;
@@ -539,7 +572,8 @@ typst_done_cb (void *cls,
   }
   if (0 != tc->active_stages)
     return;
-  GNUNET_assert (NULL == tc->t);
+  if (NULL != tc->t)
+    return; /* clean-up of a failed stage is already scheduled */
   tc->t = GNUNET_SCHEDULER_add_now (&complete_response,
                                     tc);
 }