Fix off-by-one bug in XactLogCommitRecord

alvherre · alvherre · commit ff03112bdc70 · 2018-06-15T15:00:41.000-04:00
Commit 1eb6d65 introduced zeroed alignment bytes in the GID field of commit/abort WAL records. Fixup commit cf5a189 later changed that representation into a regular cstring with a single terminating zero byte, but it also introduced an off-by-one mistake. Fix that. Author: Nikhil Sontakke Reported-by: Nikhil Sontakke Discussion: https://postgr.es/m/CAMGcDxey6dG1DP34_tJMoWPcp5sPJUAL4K5CayUUXLQSx2GQpA@mail.gmail.com
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
@@ -5365,7 +5365,7 @@ XactLogCommitRecord(TimestampTz commit_time,
 	{
 		XLogRegisterData((char *) (&xl_twophase), sizeof(xl_xact_twophase));
 		if (xl_xinfo.xinfo & XACT_XINFO_HAS_GID)
-			XLogRegisterData((char *) twophase_gid, strlen(twophase_gid));
+			XLogRegisterData((char *) twophase_gid, strlen(twophase_gid) + 1);
 	}
 
 	if (xl_xinfo.xinfo & XACT_XINFO_HAS_ORIGIN)

Original file line number	Diff line number	Diff line change
`@@ -5365,7 +5365,7 @@ XactLogCommitRecord(TimestampTz commit_time,`
`5365`	`5365`	`{`
`5366`	`5366`	`XLogRegisterData((char *) (&xl_twophase), sizeof(xl_xact_twophase));`
`5367`	`5367`	`if (xl_xinfo.xinfo & XACT_XINFO_HAS_GID)`
`5368`		`- XLogRegisterData((char *) twophase_gid, strlen(twophase_gid));`
	`5368`	`+ XLogRegisterData((char *) twophase_gid, strlen(twophase_gid) + 1);`
`5369`	`5369`	`}`
`5370`	`5370`
`5371`	`5371`	`if (xl_xinfo.xinfo & XACT_XINFO_HAS_ORIGIN)`