Preserve ignored error snapshots

include/akerror.tmpl.h

@@ -173,12 +173,12 @@ extern akerr_ErrorContext AKERR_ARRAY_ERROR[AKERR_MAX_ARRAY_ERROR];
 extern akerr_ErrorUnhandledErrorHandler akerr_handler_unhandled_error;
 extern akerr_ErrorLogFunction akerr_log_method;
 /*
- * IGNORE()'s per-thread scratch pointer. It is non-NULL only while IGNORE()
- * logs the swallowed error; IGNORE() releases the context and clears this
- * pointer before returning to its caller. Thread local only when
- * AKERR_THREAD_SAFE is 1.
+ * IGNORE()'s per-thread snapshot. IGNORE() copies the swallowed error here
+ * before releasing its pool context, so this remains a useful debugging aid
+ * after the pool slot is reused. The snapshot is read-only and is replaced by
+ * the next ignored error. Thread local only when AKERR_THREAD_SAFE is 1.
  */
-extern AKERR_THREAD_LOCAL akerr_ErrorContext *__akerr_last_ignored;
+static AKERR_THREAD_LOCAL akerr_ErrorContext __akerr_last_ignored;
 
 /*
  * Drop one reference, returning NULL once the last one is gone so the caller can
@@ -435,11 +435,20 @@ akerr_ErrorContext AKERR_NOIGNORE *__akerr_copy_string(char *destination, int ca
     FINISH_LOGIC(__err_context, true);
 
 #define IGNORE(__stmt)							\
-    __akerr_last_ignored = __stmt;					\
-    if ( __akerr_last_ignored != NULL ) {				\
-	LOG_ERROR_WITH_MESSAGE(__akerr_last_ignored, "** IGNORED ERROR **"); \
-	RELEASE_ERROR(__akerr_last_ignored);				\
-    }
+    do {								\
+	akerr_ErrorContext *__akerr_ignored = __stmt;				\
+	if ( __akerr_ignored != NULL ) {				\
+	    memcpy(&__akerr_last_ignored, __akerr_ignored,	\
+		   sizeof(__akerr_last_ignored));			\
+	    __akerr_last_ignored.stacktracebufptr =		\
+		(char *)&__akerr_last_ignored.stacktracebuf;		\
+	    akerr_ErrorContext *__akerr_ignored_snapshot =	\
+		&__akerr_last_ignored;					\
+	    LOG_ERROR_WITH_MESSAGE(__akerr_ignored_snapshot,	\
+				   "** IGNORED ERROR **");		\
+	    RELEASE_ERROR(__akerr_ignored);				\
+	}								\
+    } while ( 0 )
 
 #define CLEANUP					\
     };