include-all-tli-files-in-backup-1.patch

diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index 65200c1..5c0deaa 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -12,12 +12,13 @@
  */
 #include "postgres.h"
 
+#include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <time.h>
 
-#include "access/xlog_internal.h"		/* for pg_start/stop_backup */
+#include "access/xlog_internal.h"
 #include "catalog/pg_type.h"
 #include "lib/stringinfo.h"
 #include "libpq/libpq.h"
@@ -44,6 +45,7 @@ typedef struct
 
 
 static int64 sendDir(char *path, int basepathlen, bool sizeonly);
+static void sendTimeLineHistoryFiles(void);
 static void sendFile(char *readfilename, char *tarfilename,
 		 struct stat * statbuf);
 static void sendFileWithContent(const char *filename, const char *content);
@@ -286,6 +288,27 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
 				break;
 		}
 
+		/*
+		 * Include all timeline history files.
+		 *
+		 * The timeline history files are usually not strictly required to
+		 * restore the backup, but if you take a backup from a standby server,
+		 * and the WAL segment containing the checkpoint record contains WAL
+		 * from an older timeline, recovery will complain on the older
+		 * timeline's ID if there is no timeline history file listing it. This
+		 * can happen if you take a backup right after promoting a standby to
+		 * become new master, and take the backup from a different, cascading
+		 * standby server.
+		 *
+		 * However, even when not strictly required, the timeline history
+		 * files are tiny, and provide a lot of forensic information about the
+		 * recovery history of the database, so it's best to always include
+		 * them all. (If asked to include WAL, that is. Otherwise you need a
+		 * WAL archive to restore anyway, and the timeline history files
+		 * should be present in the archive)
+		 */
+		sendTimeLineHistoryFiles();
+
 		/* Send CopyDone message for the last tar file */
 		pq_putemptymessage('c');
 	}
@@ -726,6 +749,58 @@ sendDir(char *path, int basepathlen, bool sizeonly)
 	return size;
 }
 
+/*
+ * Include all timeline history files from pg_xlog in the output tar stream.
+ */
+static void
+sendTimeLineHistoryFiles(void)
+{
+	DIR		   *dir;
+	struct dirent *de;
+	char		pathbuf[MAXPGPATH];
+	struct stat statbuf;
+
+	dir = AllocateDir("./pg_xlog");
+	while ((de = ReadDir(dir, "./pg_xlog")) != NULL)
+	{
+		CHECK_FOR_INTERRUPTS();
+
+		if (strlen(de->d_name) == 8 + strlen(".history") &&
+			strspn(de->d_name, "0123456789ABCDEF") == 8 &&
+			strcmp(de->d_name + 8, ".history") == 0)
+		{
+			/* It looks like a timeline history file. Include it. */
+			snprintf(pathbuf, MAXPGPATH, "./pg_xlog/%s", de->d_name);
+
+			if (lstat(pathbuf, &statbuf) != 0)
+			{
+				if (errno != ENOENT)
+					ereport(ERROR,
+							(errcode_for_file_access(),
+							 errmsg("could not stat file or directory \"%s\": %m",
+									pathbuf)));
+
+				/* If the file went away while scanning, it's no error. */
+				continue;
+			}
+
+			if (!S_ISREG(statbuf.st_mode))
+			{
+				/*
+				 * Huh? It's named like a timeline history file, but isn't a
+				 * regular file.
+				 */
+				ereport(WARNING,
+						(errmsg("skipping special file \"%s\"", pathbuf)));
+				continue;
+			}
+
+			sendFile(pathbuf, pathbuf + 1, &statbuf);
+		}
+	}
+	FreeDir(dir);
+}
+
 /*****
  * Functions for handling tar file format
  *