diff options
Diffstat (limited to 'src/backend/lib/stringinfo.c')
| -rw-r--r-- | src/backend/lib/stringinfo.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/backend/lib/stringinfo.c b/src/backend/lib/stringinfo.c index 798a823ac9f..df7e01f76d9 100644 --- a/src/backend/lib/stringinfo.c +++ b/src/backend/lib/stringinfo.c @@ -77,12 +77,15 @@ resetStringInfo(StringInfo str) void appendStringInfo(StringInfo str, const char *fmt,...) { + int save_errno = errno; + for (;;) { va_list args; int needed; /* Try to format the data. */ + errno = save_errno; va_start(args, fmt); needed = appendStringInfoVA(str, fmt, args); va_end(args); @@ -105,6 +108,9 @@ appendStringInfo(StringInfo str, const char *fmt,...) * pass the return value to enlargeStringInfo() before trying again; see * appendStringInfo for standard usage pattern. * + * Caution: callers must be sure to preserve their entry-time errno + * when looping, in case the fmt contains "%m". + * * XXX This API is ugly, but there seems no alternative given the C spec's * restrictions on what can portably be done with va_list arguments: you have * to redo va_start before you can rescan the argument list, and we can't do |