Properly check for readdir/closedir() failures

Clear errno before calling readdir() and handle old MinGW errno bug
while adding full test coverage for readdir/closedir failures.

Backpatch through 8.4.

src/backend/storage/file/fd.c

@@ -1687,11 +1687,7 @@ ReadDir(DIR *dir, const char *dirname)
 		return dent;
 
 #ifdef WIN32
-
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif

src/bin/pg_resetxlog/pg_resetxlog.c

@@ -742,8 +742,7 @@ FindEndOfXLOG(void)
 		exit(1);
 	}
 
-	errno = 0;
-	while ((xlde = readdir(xldir)) != NULL)
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
 	{
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
@@ -767,25 +766,27 @@ FindEndOfXLOG(void)
 				newXlogSeg = seg;
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+#ifdef WIN32
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, XLOGDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 
 	/*
 	 * Finally, convert to new xlog seg size, and advance by one to ensure we
@@ -817,8 +818,7 @@ KillExistingXLOG(void)
 		exit(1);
 	}
 
-	errno = 0;
-	while ((xlde = readdir(xldir)) != NULL)
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
 	{
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
@@ -831,25 +831,27 @@ KillExistingXLOG(void)
 				exit(1);
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+#ifdef WIN32
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, XLOGDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 }
 
 
@@ -873,8 +875,7 @@ KillExistingArchiveStatus(void)
 		exit(1);
 	}
 
-	errno = 0;
-	while ((xlde = readdir(xldir)) != NULL)
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
 	{
 		if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
 			(strcmp(xlde->d_name + 24, ".ready") == 0 ||
@@ -888,25 +889,27 @@ KillExistingArchiveStatus(void)
 				exit(1);
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+#ifdef WIN32
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, ARCHSTATDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, ARCHSTATDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 }
 
 

src/port/dirent.c

@@ -105,15 +105,19 @@ readdir(DIR *d)
 	strcpy(d->ret.d_name, fd.cFileName);		/* Both strings are MAX_PATH
 												 * long */
 	d->ret.d_namlen = strlen(d->ret.d_name);
+
 	return &d->ret;
 }
 
 int
 closedir(DIR *d)
 {
+	int ret = 0;
+
 	if (d->handle != INVALID_HANDLE_VALUE)
-		FindClose(d->handle);
+		ret = !FindClose(d->handle);
 	free(d->dirname);
 	free(d);
-	return 0;
+
+	return ret;
 }

src/port/dirmod.c

@@ -448,8 +448,7 @@ pgfnames(const char *path)
 
 	filenames = (char **) palloc(fnsize * sizeof(char *));
 
-	errno = 0;
-	while ((file = readdir(dir)) != NULL)
+	while (errno = 0, (file = readdir(dir)) != NULL)
 	{
 		if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0)
 		{
@@ -461,17 +460,14 @@ pgfnames(const char *path)
 			}
 			filenames[numnames++] = pstrdup(file->d_name);
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+#ifdef WIN32
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
+
 	if (errno)
 	{
 #ifndef FRONTEND
@@ -484,7 +480,15 @@ pgfnames(const char *path)
 
 	filenames[numnames] = NULL;
 
-	closedir(dir);
+	if (closedir(dir))
+	{
+#ifndef FRONTEND
+		elog(WARNING, "could not close directory \"%s\": %m", path);
+#else
+		fprintf(stderr, _("could not close directory \"%s\": %s\n"),
+				path, strerror(errno));
+#endif
+	}
 
 	return filenames;
 }

src/port/pgcheckdir.c

@@ -32,14 +32,12 @@ pg_check_dir(const char *dir)
 	DIR		   *chkdir;
 	struct dirent *file;
 
-	errno = 0;
-
 	chkdir = opendir(dir);
 
 	if (chkdir == NULL)
 		return (errno == ENOENT) ? 0 : -1;
 
-	while ((file = readdir(chkdir)) != NULL)
+	while (errno = 0, (file = readdir(chkdir)) != NULL)
 	{
 		if (strcmp(".", file->d_name) == 0 ||
 			strcmp("..", file->d_name) == 0)
@@ -55,18 +53,12 @@ pg_check_dir(const char *dir)
 	}
 
 #ifdef WIN32
-
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
-	closedir(chkdir);
-
-	if (errno != 0)
+	if (errno || closedir(chkdir))
 		result = -1;			/* some kind of I/O error? */
 
 	return result;