Fix nested error handling in PG_FINALLY

We need to pop the error stack before running the user-supplied
PG_FINALLY code.  Otherwise an error in the cleanup code would end up
at the same sigsetjmp() invocation and result in an infinite error
handling loop.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com

diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 3bc17164312c548b4723f210ddc979c2a507d7db..1ec16f49b296d9d058eafa7de071809d5c899a26 100644 (file)
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -3868,7 +3868,7 @@ xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt)
 
                        result = xmlBuffer_to_xmltype(buf);
                }
-               PG_FINALLY()
+               PG_FINALLY();
                {
                        if (nodefree)
                                nodefree(cur_copy);

diff --git a/src/include/utils/elog.h b/src/include/utils/elog.h
index 853c2e0709ed92f92c02937db118c9ff6be1ad14..47412a831f096acb84c84fb09ee577820d479766 100644 (file)
--- a/src/include/utils/elog.h
+++ b/src/include/utils/elog.h
@@ -338,14 +338,16 @@ extern PGDLLIMPORT ErrorContextCallback *error_context_stack;
                } \
                else \
                        _do_rethrow = true; \
-               {
+               { \
+                       PG_exception_stack = _save_exception_stack; \
+                       error_context_stack = _save_context_stack
 
 #define PG_END_TRY()  \
                } \
-               PG_exception_stack = _save_exception_stack; \
-               error_context_stack = _save_context_stack; \
                if (_do_rethrow) \
                                PG_RE_THROW(); \
+               PG_exception_stack = _save_exception_stack; \
+               error_context_stack = _save_context_stack; \
        } while (0)
 
 /*