From: Andres Freund <andres@anarazel.de>
Date: Sun, 4 Jan 2015 14:35:46 +0000 (+0100)
Subject: Fix off-by-one in pg_xlogdump's fuzzy_open_file().
X-Git-Tag: REL9_4_1~65
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=835a48702e550b6c9958bb053aa6c458971536d0;p=postgresql

Fix off-by-one in pg_xlogdump's fuzzy_open_file().

In the unlikely case of stdin (fd 0) being closed, the off-by-one
would lead to pg_xlogdump failing to open files.

Spotted by Coverity.

Backpatch to 9.3 where pg_xlogdump was introduced.
---

diff --git a/contrib/pg_xlogdump/pg_xlogdump.c b/contrib/pg_xlogdump/pg_xlogdump.c
index 824b8c393c..37a4c44acd 100644
--- a/contrib/pg_xlogdump/pg_xlogdump.c
+++ b/contrib/pg_xlogdump/pg_xlogdump.c
@@ -152,7 +152,7 @@ fuzzy_open_file(const char *directory, const char *fname)
 		fd = open(fname, O_RDONLY | PG_BINARY, 0);
 		if (fd < 0 && errno != ENOENT)
 			return -1;
-		else if (fd > 0)
+		else if (fd >= 0)
 			return fd;
 
 		/* XLOGDIR / fname */
@@ -161,7 +161,7 @@ fuzzy_open_file(const char *directory, const char *fname)
 		fd = open(fpath, O_RDONLY | PG_BINARY, 0);
 		if (fd < 0 && errno != ENOENT)
 			return -1;
-		else if (fd > 0)
+		else if (fd >= 0)
 			return fd;
 
 		datadir = getenv("PGDATA");
@@ -173,7 +173,7 @@ fuzzy_open_file(const char *directory, const char *fname)
 			fd = open(fpath, O_RDONLY | PG_BINARY, 0);
 			if (fd < 0 && errno != ENOENT)
 				return -1;
-			else if (fd > 0)
+			else if (fd >= 0)
 				return fd;
 		}
 	}
@@ -185,7 +185,7 @@ fuzzy_open_file(const char *directory, const char *fname)
 		fd = open(fpath, O_RDONLY | PG_BINARY, 0);
 		if (fd < 0 && errno != ENOENT)
 			return -1;
-		else if (fd > 0)
+		else if (fd >= 0)
 			return fd;
 
 		/* directory / XLOGDIR / fname */
@@ -194,7 +194,7 @@ fuzzy_open_file(const char *directory, const char *fname)
 		fd = open(fpath, O_RDONLY | PG_BINARY, 0);
 		if (fd < 0 && errno != ENOENT)
 			return -1;
-		else if (fd > 0)
+		else if (fd >= 0)
 			return fd;
 	}
 	return -1;