04-tarutils-v2.patch

diff -durpN postgresql.3/src/backend/replication/basebackup.c postgresql.4/src/backend/replication/basebackup.c
--- postgresql.3/src/backend/replication/basebackup.c	2012-10-06 19:25:21.002166521 +0200
+++ postgresql.4/src/backend/replication/basebackup.c	2012-11-21 18:15:21.764511960 +0100
@@ -721,48 +721,12 @@ sendDir(char *path, int basepathlen, boo
 
 
 /*
- * Utility routine to print possibly larger than 32 bit integers in a
- * portable fashion.  Filled with zeros.
- */
-static void
-print_val(char *s, uint64 val, unsigned int base, size_t len)
-{
-	int			i;
-
-	for (i = len; i > 0; i--)
-	{
-		int			digit = val % base;
-
-		s[i - 1] = '0' + digit;
-		val = val / base;
-	}
-}
-
-/*
  * Maximum file size for a tar member: The limit inherent in the
  * format is 2^33-1 bytes (nearly 8 GB).  But we don't want to exceed
  * what we can represent in pgoff_t.
  */
 #define MAX_TAR_MEMBER_FILELEN (((int64) 1 << Min(33, sizeof(pgoff_t)*8 - 1)) - 1)
 
-static int
-_tarChecksum(char *header)
-{
-	int			i,
-				sum;
-
-	/*
-	 * Per POSIX, the checksum is the simple sum of all bytes in the header,
-	 * treating the bytes as unsigned, and treating the checksum field (at
-	 * offset 148) as though it contained 8 spaces.
-	 */
-	sum = 8 * ' ';				/* presumed value for checksum field */
-	for (i = 0; i < 512; i++)
-		if (i < 148 || i >= 156)
-			sum += 0xFF & header[i];
-	return sum;
-}
-
 /* Given the member, write the TAR header & send the file */
 static void
 sendFile(char *readfilename, char *tarfilename, struct stat * statbuf)
@@ -840,94 +804,12 @@ _tarWriteHeader(const char *filename, co
 {
 	char		h[512];
 
-	/*
-	 * Note: most of the fields in a tar header are not supposed to be
-	 * null-terminated.  We use sprintf, which will write a null after the
-	 * required bytes; that null goes into the first byte of the next field.
-	 * This is okay as long as we fill the fields in order.
-	 */
-	memset(h, 0, sizeof(h));
-
-	/* Name 100 */
-	sprintf(&h[0], "%.99s", filename);
-	if (linktarget != NULL || S_ISDIR(statbuf->st_mode))
-	{
-		/*
-		 * We only support symbolic links to directories, and this is
-		 * indicated in the tar format by adding a slash at the end of the
-		 * name, the same as for regular directories.
-		 */
-		int			flen = strlen(filename);
-
-		flen = Min(flen, 99);
-		h[flen] = '/';
-		h[flen + 1] = '\0';
-	}
-
-	/* Mode 8 */
-	sprintf(&h[100], "%07o ", (int) statbuf->st_mode);
-
-	/* User ID 8 */
-	sprintf(&h[108], "%07o ", statbuf->st_uid);
-
-	/* Group 8 */
-	sprintf(&h[116], "%07o ", statbuf->st_gid);
-
-	/* File size 12 - 11 digits, 1 space; use print_val for 64 bit support */
-	if (linktarget != NULL || S_ISDIR(statbuf->st_mode))
-		/* Symbolic link or directory has size zero */
-		print_val(&h[124], 0, 8, 11);
-	else
-		print_val(&h[124], statbuf->st_size, 8, 11);
-	sprintf(&h[135], " ");
-
-	/* Mod Time 12 */
-	sprintf(&h[136], "%011o ", (int) statbuf->st_mtime);
-
-	/* Checksum 8 cannot be calculated until we've filled all other fields */
-
-	if (linktarget != NULL)
-	{
-		/* Type - Symbolic link */
-		sprintf(&h[156], "2");
-		/* Link Name 100 */
-		sprintf(&h[157], "%.99s", linktarget);
-	}
-	else if (S_ISDIR(statbuf->st_mode))
-		/* Type - directory */
-		sprintf(&h[156], "5");
-	else
-		/* Type - regular file */
-		sprintf(&h[156], "0");
-
-	/* Magic 6 */
-	sprintf(&h[257], "ustar");
-
-	/* Version 2 */
-	sprintf(&h[263], "00");
-
-	/* User 32 */
-	/* XXX: Do we need to care about setting correct username? */
-	sprintf(&h[265], "%.31s", "postgres");
-
-	/* Group 32 */
-	/* XXX: Do we need to care about setting correct group name? */
-	sprintf(&h[297], "%.31s", "postgres");
-
-	/* Major Dev 8 */
-	sprintf(&h[329], "%07o ", 0);
-
-	/* Minor Dev 8 */
-	sprintf(&h[337], "%07o ", 0);
-
-	/* Prefix 155 - not used, leave as nulls */
-
-	/*
-	 * We mustn't overwrite the next field while inserting the checksum.
-	 * Fortunately, the checksum can't exceed 6 octal digits, so we just write
-	 * 6 digits, a space, and a null, which is legal per POSIX.
-	 */
-	sprintf(&h[148], "%06o ", _tarChecksum(h));
+	_tarCreateHeader(h, filename, linktarget,
+						statbuf->st_size,
+						statbuf->st_mode,
+						statbuf->st_uid,
+						statbuf->st_gid,
+						statbuf->st_mtime);
 
 	/* Now send the completed header. */
 	pq_putmessage('d', h, 512);
diff -durpN postgresql.3/src/bin/initdb/initdb.c postgresql.4/src/bin/initdb/initdb.c
--- postgresql.3/src/bin/initdb/initdb.c	2012-11-21 18:03:54.547749709 +0100
+++ postgresql.4/src/bin/initdb/initdb.c	2012-11-21 18:27:34.223704650 +0100
@@ -218,7 +218,6 @@ static void make_postgres(void);
 static void perform_fsync(void);
 static void trapsig(int signum);
 static void check_ok(void);
-static char *escape_quotes(const char *src);
 static int	locale_date_order(const char *locale);
 static bool check_locale_name(int category, const char *locale,
 				  char **canonname);
@@ -2342,35 +2341,6 @@ check_ok(void)
 	}
 }
 
-/*
- * Escape (by doubling) any single quotes or backslashes in given string
- *
- * Note: this is used to process both postgresql.conf entries and SQL
- * string literals.  Since postgresql.conf strings are defined to treat
- * backslashes as escapes, we have to double backslashes here.	Hence,
- * when using this for a SQL string literal, use E'' syntax.
- *
- * We do not need to worry about encoding considerations because all
- * valid backend encodings are ASCII-safe.
- */
-static char *
-escape_quotes(const char *src)
-{
-	int			len = strlen(src),
-				i,
-				j;
-	char	   *result = pg_malloc(len * 2 + 1);
-
-	for (i = 0, j = 0; i < len; i++)
-	{
-		if (SQL_STR_DOUBLE(src[i], true))
-			result[j++] = src[i];
-		result[j++] = src[i];
-	}
-	result[j] = '\0';
-	return result;
-}
-
 /* Hack to suppress a warning about %x from some versions of gcc */
 static inline size_t
 my_strftime(char *s, size_t max, const char *fmt, const struct tm * tm)
diff -durpN postgresql.3/src/bin/pg_basebackup/pg_basebackup.c postgresql.4/src/bin/pg_basebackup/pg_basebackup.c
--- postgresql.3/src/bin/pg_basebackup/pg_basebackup.c	2012-11-21 18:05:17.308315854 +0100
+++ postgresql.4/src/bin/pg_basebackup/pg_basebackup.c	2012-11-21 18:28:02.647904139 +0100
@@ -26,7 +26,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <time.h>
 
 #ifdef HAVE_LIBZ
 #include <zlib.h>
@@ -73,8 +72,6 @@ static int	has_xlogendptr = 0;
 static volatile LONG has_xlogendptr = 0;
 #endif
 
-/* Don't ever change this value, the TAR file format requires it. */
-#define TARCHUNKSZ	512
 PQExpBuffer rcExpBuf = NULL;
 
 /* Function headers */
@@ -84,13 +81,8 @@ static void progress_report(int tablespa
 
 static void ReceiveTarFile(PGconn *conn, PGresult *res, int rownum);
 static void ReceiveAndUnpackTarFile(PGconn *conn, PGresult *res, int rownum);
-static char *escape_quotes(const char *src);
 static void CreateRecoveryConf(PGconn *conn);
 static void WriteRecoveryConf(void);
-static int  _tarChecksum(char *header);
-static void print_val(char *s, uint64 val, unsigned int base, size_t len);
-static void scan_val(char *s, uint64 *val, unsigned int base, size_t len);
-static void _tarCreateHeader(char *header, char *filename, size_t filesize);
 static void BaseBackup(void);
 
 static bool reached_end_position(XLogRecPtr segendpos, uint32 timeline,
@@ -683,7 +675,10 @@ ReceiveTarFile(PGconn *conn, PGresult *r
 				char		header[TARCHUNKSZ];
 				int		padding;
 
-				_tarCreateHeader(header, "recovery.conf", rcExpBuf->len);
+				_tarCreateHeader(header, "recovery.conf", NULL,
+									rcExpBuf->len,
+									0600, 04000, 02000,
+									time(NULL));
 
 				padding = ((rcExpBuf->len + (TARCHUNKSZ-1)) & ~(TARCHUNKSZ-1)) - rcExpBuf->len;
 
@@ -1110,152 +1105,6 @@ ReceiveAndUnpackTarFile(PGconn *conn, PG
 		WriteRecoveryConf();
 }
 
-static int
-_tarChecksum(char *header)
-{
-	int			i,
-				sum;
-
-	/*
-	 * Per POSIX, the checksum is the simple sum of all bytes in the header,
-	 * treating the bytes as unsigned, and treating the checksum field (at
-	 * offset 148) as though it contained 8 spaces.
-	 */
-	sum = 8 * ' ';				/* presumed value for checksum field */
-	for (i = 0; i < TARCHUNKSZ; i++)
-		if (i < 148 || i >= 156)
-			sum += 0xFF & header[i];
-	return sum;
-}
-
-
-/*
- * Utility routine to print possibly larger than 32 bit integers in a
- * portable fashion.  Filled with zeros.
- */
-static void
-print_val(char *s, uint64 val, unsigned int base, size_t len)
-{
-	int			i;
-
-	for (i = len; i > 0; i--)
-	{
-		int			digit = val % base;
-
-		s[i - 1] = '0' + digit;
-		val = val / base;
-	}
-}
-
-
-/*
- * Inverse for print_val()
- */
-static void
-scan_val(char *s, uint64 *val, unsigned int base, size_t len)
-{
-	uint64			tmp = 0;
-	int			i;
-
-	for (i = 0; i < len; i++)
-	{
-		int			digit = s[i] - '0';
-
-		tmp = tmp * base + digit;
-	}
-
-	*val = tmp;
-}
-
-
-static void
-_tarCreateHeader(char *header, char *filename, size_t filesize)
-{
-	/*
-	 * Note: most of the fields in a tar header are not supposed to be
-	 * null-terminated.  We use sprintf, which will write a null after the
-	 * required bytes; that null goes into the first byte of the next field.
-	 * This is okay as long as we fill the fields in order.
-	 */
-	memset(header, 0, TARCHUNKSZ /* sizeof the tar header */);
-
-	/* Name 100 */
-	sprintf(&header[0], "%.99s", filename);
-
-	/* Mode 8 */
-	sprintf(&header[100], "0000600 ");
-
-	/* User ID 8 */
-	sprintf(&header[108], "0004000 ");
-
-	/* Group 8 */
-	sprintf(&header[116], "0002000 ");
-
-	/* File size 12 - 11 digits, 1 space; use print_val for 64 bit support */
-	print_val(&header[124], filesize, 8, 11);
-	sprintf(&header[135], " ");
-
-	/* Mod Time 12 */
-	sprintf(&header[136], "%011o ", (int) time(NULL));
-
-	/* Checksum 8 cannot be calculated until we've filled all other fields */
-
-	/* Type - regular file */
-	sprintf(&header[156], "0");
-
-	/* Link Name 100 (leave as nulls) */
-
-	/* Magic 6 */
-	sprintf(&header[257], "ustar");
-
-	/* Version 2 */
-	sprintf(&header[263], "00");
-
-	/* User 32 */
-	/* XXX: Do we need to care about setting correct username? */
-	sprintf(&header[265], "%.31s", "postgres");
-
-	/* Group 32 */
-	/* XXX: Do we need to care about setting correct group name? */
-	sprintf(&header[297], "%.31s", "postgres");
-
-	/* Major Dev 8 */
-	sprintf(&header[329], "%07o ", 0);
-
-	/* Minor Dev 8 */
-	sprintf(&header[337], "%07o ", 0);
-
-	/* Prefix 155 - not used, leave as nulls */
-
-	/*
-	 * We mustn't overwrite the next field while inserting the checksum.
-	 * Fortunately, the checksum can't exceed 6 octal digits, so we just write
-	 * 6 digits, a space, and a null, which is legal per POSIX.
-	 */
-	sprintf(&header[148], "%06o ", _tarChecksum(header));
-}
-
-/*
- * Escape single quotes in a string
- */
-static char *
-escape_quotes(const char *src)
-{
-	int			len = strlen(src),
-				i,
-				j;
-	char	   *result = pg_malloc(len * 2 + 1);
-
-	for (i = 0, j = 0; i < len; i++)
-	{
-		if (SQL_STR_DOUBLE(src[i], true))
-			result[j++] = src[i];
-		result[j++] = src[i];
-	}
-	result[j] = '\0';
-	return result;
-}
-
 /*
  * Try to create recovery.conf in memory and set the length to write later.
  */
diff -durpN postgresql.3/src/bin/pg_dump/pg_backup_tar.c postgresql.4/src/bin/pg_dump/pg_backup_tar.c
--- postgresql.3/src/bin/pg_dump/pg_backup_tar.c	2012-11-21 16:59:40.614991367 +0100
+++ postgresql.4/src/bin/pg_dump/pg_backup_tar.c	2012-11-21 18:15:21.767511985 +0100
@@ -114,7 +114,6 @@ static char *tarGets(char *buf, size_t l
 static int	tarPrintf(ArchiveHandle *AH, TAR_MEMBER *th, const char *fmt,...) __attribute__((format(PG_PRINTF_ATTRIBUTE, 3, 4)));
 
 static void _tarAddFile(ArchiveHandle *AH, TAR_MEMBER *th);
-static int	_tarChecksum(char *th);
 static TAR_MEMBER *_tarPositionTo(ArchiveHandle *AH, const char *filename);
 static size_t tarRead(void *buf, size_t len, TAR_MEMBER *th);
 static size_t tarWrite(const void *buf, size_t len, TAR_MEMBER *th);
@@ -1015,24 +1014,6 @@ tarPrintf(ArchiveHandle *AH, TAR_MEMBER
 	return cnt;
 }
 
-static int
-_tarChecksum(char *header)
-{
-	int			i,
-				sum;
-
-	/*
-	 * Per POSIX, the checksum is the simple sum of all bytes in the header,
-	 * treating the bytes as unsigned, and treating the checksum field (at
-	 * offset 148) as though it contained 8 spaces.
-	 */
-	sum = 8 * ' ';				/* presumed value for checksum field */
-	for (i = 0; i < 512; i++)
-		if (i < 148 || i >= 156)
-			sum += 0xFF & header[i];
-	return sum;
-}
-
 bool
 isValidTarHeader(char *header)
 {
@@ -1304,94 +1285,16 @@ _tarGetHeader(ArchiveHandle *AH, TAR_MEM
 }
 
 
-/*
- * Utility routine to print possibly larger than 32 bit integers in a
- * portable fashion.  Filled with zeros.
- */
-static void
-print_val(char *s, uint64 val, unsigned int base, size_t len)
-{
-	int			i;
-
-	for (i = len; i > 0; i--)
-	{
-		int			digit = val % base;
-
-		s[i - 1] = '0' + digit;
-		val = val / base;
-	}
-}
-
-
 static void
 _tarWriteHeader(TAR_MEMBER *th)
 {
 	char		h[512];
 
-	/*
-	 * Note: most of the fields in a tar header are not supposed to be
-	 * null-terminated.  We use sprintf, which will write a null after the
-	 * required bytes; that null goes into the first byte of the next field.
-	 * This is okay as long as we fill the fields in order.
-	 */
-	memset(h, 0, sizeof(h));
-
-	/* Name 100 */
-	sprintf(&h[0], "%.99s", th->targetFile);
-
-	/* Mode 8 */
-	sprintf(&h[100], "0000600 ");
-
-	/* User ID 8 */
-	sprintf(&h[108], "0004000 ");
-
-	/* Group 8 */
-	sprintf(&h[116], "0002000 ");
-
-	/* File size 12 - 11 digits, 1 space; use print_val for 64 bit support */
-	print_val(&h[124], th->fileLen, 8, 11);
-	sprintf(&h[135], " ");
-
-	/* Mod Time 12 */
-	sprintf(&h[136], "%011o ", (int) time(NULL));
-
-	/* Checksum 8 cannot be calculated until we've filled all other fields */
-
-	/* Type - regular file */
-	sprintf(&h[156], "0");
-
-	/* Link Name 100 (leave as nulls) */
-
-	/* Magic 6 */
-	sprintf(&h[257], "ustar");
-
-	/* Version 2 */
-	sprintf(&h[263], "00");
-
-	/* User 32 */
-	/* XXX: Do we need to care about setting correct username? */
-	sprintf(&h[265], "%.31s", "postgres");
-
-	/* Group 32 */
-	/* XXX: Do we need to care about setting correct group name? */
-	sprintf(&h[297], "%.31s", "postgres");
-
-	/* Major Dev 8 */
-	sprintf(&h[329], "%07o ", 0);
-
-	/* Minor Dev 8 */
-	sprintf(&h[337], "%07o ", 0);
-
-	/* Prefix 155 - not used, leave as nulls */
-
-	/*
-	 * We mustn't overwrite the next field while inserting the checksum.
-	 * Fortunately, the checksum can't exceed 6 octal digits, so we just write
-	 * 6 digits, a space, and a null, which is legal per POSIX.
-	 */
-	sprintf(&h[148], "%06o ", _tarChecksum(h));
+	_tarCreateHeader(h, th->targetFile, NULL,
+					  th->fileLen,
+					  0600, 04000, 02000,
+					  time(NULL));
 
-	/* Now write the completed header. */
 	if (fwrite(h, 1, 512, th->tarFH) != 512)
 		exit_horribly(modulename, "could not write to output file: %s\n", strerror(errno));
 }
diff -durpN postgresql.3/src/include/port.h postgresql.4/src/include/port.h
--- postgresql.3/src/include/port.h	2012-11-21 18:02:18.860095054 +0100
+++ postgresql.4/src/include/port.h	2012-11-21 18:27:22.006619619 +0100
@@ -16,6 +16,7 @@
 #include <ctype.h>
 #include <netdb.h>
 #include <pwd.h>
+#include <time.h>
 
 /* port/init.c */
 typedef void (*fe_func)(void);
@@ -491,4 +492,22 @@ extern void pg_free(void *ptr);
 /* port/pgmkdirp.c */
 extern int	pg_mkdir_p(char *path, int omode);
 
+/* port/strutil.c */
+extern void	print_val(char *s, uint64 val, unsigned int base, size_t len);
+extern void	scan_val(char *s, uint64 *val, unsigned int base, size_t len);
+extern char *escape_quotes(const char *src);
+
+/* port/tarutil.c */
+
+/* Don't ever change this value, the TAR file format requires it. */
+#define TARCHUNKSZ      512
+
+extern int	_tarChecksum(char *header);
+extern void	_tarCreateHeader(char *header,
+				const char *filename,
+				const char *linktarget,
+				int64 filesize, int st_mode,
+				int st_uid, int st_gid,
+				time_t  mtime);
+
 #endif   /* PG_PORT_H */
diff -durpN postgresql.3/src/port/Makefile postgresql.4/src/port/Makefile
--- postgresql.3/src/port/Makefile	2012-11-21 16:18:29.251969612 +0100
+++ postgresql.4/src/port/Makefile	2012-11-21 18:18:11.002685027 +0100
@@ -33,7 +33,7 @@ LIBS += $(PTHREAD_LIBS)
 OBJS = $(LIBOBJS) chklocale.o dirmod.o erand48.o exec.o fls.o init.o \
 	inet_net_ntop.o noblock.o path.o pgcheckdir.o pg_crc.o pgmalloc.o \
 	pgmkdirp.o pgsleep.o pgstrcasecmp.o qsort.o qsort_arg.o sprompt.o \
-	thread.o
+	strutil.o tarutil.o thread.o
 
 # foo_srv.o and foo.o are both built from foo.c, but only foo.o has -DFRONTEND
 OBJS_SRV = $(OBJS:%.o=%_srv.o)
diff -durpN postgresql.3/src/port/strutil.c postgresql.4/src/port/strutil.c
--- postgresql.3/src/port/strutil.c	1970-01-01 01:00:00.000000000 +0100
+++ postgresql.4/src/port/strutil.c	2012-11-21 18:33:28.833248501 +0100
@@ -0,0 +1,87 @@
+/*-------------------------------------------------------------------------
+ *
+ * strutil.c
+ *	  common string functions
+ *
+ * IDENTIFICATION
+ *	  src/port/strutil.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#include "utils/palloc.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+/*
+ * Utility routine to print possibly larger than 32 bit integers in a
+ * portable fashion.  Filled with zeros.
+ */
+void
+print_val(char *s, uint64 val, unsigned int base, size_t len)
+{
+	int			i;
+
+	for (i = len; i > 0; i--)
+	{
+		int			digit = val % base;
+
+		s[i - 1] = '0' + digit;
+		val = val / base;
+	}
+}
+
+
+/*
+ * Inverse of print_val()
+ */
+void
+scan_val(char *s, uint64 *val, unsigned int base, size_t len)
+{
+	uint64			tmp = 0;
+	int			i;
+
+	for (i = 0; i < len; i++)
+	{
+		int			digit = s[i] - '0';
+
+		tmp = tmp * base + digit;
+	}
+
+	*val = tmp;
+}
+
+/*
+ * Escape (by doubling) any single quotes or backslashes in given string
+ *
+ * Note: this is used to process both postgresql.conf entries and SQL
+ * string literals.  Since postgresql.conf strings are defined to treat
+ * backslashes as escapes, we have to double backslashes here.	Hence,
+ * when using this for a SQL string literal, use E'' syntax.
+ *
+ * We do not need to worry about encoding considerations because all
+ * valid backend encodings are ASCII-safe.
+ */
+char *
+escape_quotes(const char *src)
+{
+	int			len = strlen(src),
+				i,
+				j;
+#ifdef FRONTEND
+	char	   *result = pg_malloc(len * 2 + 1);
+#else
+	char	   *result = palloc(len * 2 + 1);
+#endif
+
+	for (i = 0, j = 0; i < len; i++)
+	{
+		if (SQL_STR_DOUBLE(src[i], true))
+			result[j++] = src[i];
+		result[j++] = src[i];
+	}
+	result[j] = '\0';
+	return result;
+}
diff -durpN postgresql.3/src/port/tarutil.c postgresql.4/src/port/tarutil.c
--- postgresql.3/src/port/tarutil.c	1970-01-01 01:00:00.000000000 +0100
+++ postgresql.4/src/port/tarutil.c	2012-11-21 18:16:25.537953568 +0100
@@ -0,0 +1,135 @@
+/*-------------------------------------------------------------------------
+ *
+ * tarutil.c
+ *	  common functions for handling the TAR format
+ *
+ * IDENTIFICATION
+ *	  src/port/tarutil.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <sys/stat.h>
+
+int
+_tarChecksum(char *header)
+{
+	int			i,
+				sum;
+
+	/*
+	 * Per POSIX, the checksum is the simple sum of all bytes in the header,
+	 * treating the bytes as unsigned, and treating the checksum field (at
+	 * offset 148) as though it contained 8 spaces.
+	 */
+	sum = 8 * ' ';				/* presumed value for checksum field */
+	for (i = 0; i < TARCHUNKSZ; i++)
+		if (i < 148 || i >= 156)
+			sum += 0xFF & header[i];
+	return sum;
+}
+
+
+void
+_tarCreateHeader(char *header, const char *filename,
+				const char *linktarget,
+				int64 filesize, int st_mode,
+				int st_uid, int st_gid,
+				time_t mtime)
+{
+	/*
+	 * Note: most of the fields in a tar header are not supposed to be
+	 * null-terminated.  We use sprintf, which will write a null after the
+	 * required bytes; that null goes into the first byte of the next field.
+	 * This is okay as long as we fill the fields in order.
+	 */
+	memset(header, 0, TARCHUNKSZ /* sizeof the tar header */);
+
+	/* Name 100 */
+	sprintf(&header[0], "%.99s", filename);
+	if (linktarget != NULL || S_ISDIR(st_mode))
+	{
+		/*
+		 * We only support symbolic links to directories, and this is
+		 * indicated in the tar format by adding a slash at the end of the
+		 * name, the same as for regular directories.
+		 */
+		int	flen = strlen(filename);
+
+		flen = Min(flen, 99);
+		header[flen] = '/';
+		header[flen + 1] = '\0';
+	}
+
+	/* Mode 8 */
+	sprintf(&header[100], "%07o ", st_mode);
+
+	/* User ID 8 */
+	sprintf(&header[108], "%07o ", st_uid);
+
+	/* Group 8 */
+	sprintf(&header[116], "%07o ", st_gid);
+
+	/* File size 12 - 11 digits, 1 space; use print_val for 64 bit support */
+	if (linktarget != NULL || S_ISDIR(st_mode))
+		/* Symbolic link or directory has size zero */
+		print_val(&header[124], 0, 8, 11);
+	else
+		print_val(&header[124], filesize, 8, 11);
+	sprintf(&header[135], " ");
+
+	/* Mod Time 12 - 11 digits, 1 space; use print_val for 64 bit support */
+	print_val(&header[136], mtime, 8, 11);
+	sprintf(&header[147], " ");
+
+	/* Checksum 8 cannot be calculated until we've filled all other fields */
+
+	if (linktarget != NULL)
+	{
+		/* Type - Symbolic link */
+		sprintf(&header[156], "2");
+		/* Link Name 100 */
+		sprintf(&header[157], "%.99s", linktarget);
+	}
+	else if (S_ISDIR(st_mode))
+		/* Type - directory */
+		sprintf(&header[156], "5");
+	else
+		/* Type - regular file */
+		sprintf(&header[156], "0");
+
+	/* Magic 6 */
+	sprintf(&header[257], "ustar");
+
+	/* Version 2 */
+	sprintf(&header[263], "00");
+
+	/* User 32 */
+	/* XXX: Do we need to care about setting correct username? */
+	sprintf(&header[265], "%.31s", "postgres");
+
+	/* Group 32 */
+	/* XXX: Do we need to care about setting correct group name? */
+	sprintf(&header[297], "%.31s", "postgres");
+
+	/* Major Dev 8 */
+	sprintf(&header[329], "%07o ", 0);
+
+	/* Minor Dev 8 */
+	sprintf(&header[337], "%07o ", 0);
+
+	/* Prefix 155 - not used, leave as nulls */
+
+	/*
+	 * We mustn't overwrite the next field while inserting the checksum.
+	 * Fortunately, the checksum can't exceed 6 octal digits, so we just write
+	 * 6 digits, a space, and a null, which is legal per POSIX.
+	 */
+	sprintf(&header[148], "%06o ", _tarChecksum(header));
+}
+