pg_waldump: Fix small memory leak when rmgr->rm_identify returns NULL.

This got broken in 604f7956b94, shortly after rm_identify's
introduction.

Author: Andres Freund
Discussion: https://postgr.es/m/20191029233341.4gnyau7e5v2lh5sc@alap3.anarazel.de
Backpatch: 9.5, where rm_identify was introduced

diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 2f40c559adfb9d6284238ca8bdce22f7fa69650a..4e1df66c48a911abb7522395a995dfa45a87e56c 100644 (file)
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -542,17 +542,18 @@ XLogDumpDisplayRecord(XLogDumpConfig *config, XLogReaderState *record)
 
    XLogDumpRecordLen(record, &rec_len, &fpi_len);
 
-   id = desc->rm_identify(info);
-   if (id == NULL)
-       id = psprintf("UNKNOWN (%x)", info & ~XLR_INFO_MASK);
-
    printf("rmgr: %-11s len (rec/tot): %6u/%6u, tx: %10u, lsn: %X/%08X, prev %X/%08X, ",
           desc->rm_name,
           rec_len, XLogRecGetTotalLen(record),
           XLogRecGetXid(record),
           (uint32) (record->ReadRecPtr >> 32), (uint32) record->ReadRecPtr,
           (uint32) (xl_prev >> 32), (uint32) xl_prev);
-   printf("desc: %s ", id);
+
+   id = desc->rm_identify(info);
+   if (id == NULL)
+       printf("desc: UNKNOWN (%x) ", info & ~XLR_INFO_MASK);
+   else
+       printf("desc: %s ", id);
 
    /* the desc routine will printf the description directly to stdout */
    desc->rm_desc(NULL, record);