Fix pg_rewind with in-place tablespaces when source is remote

libpq_source.c would consider any result returned by
pg_tablespace_location() as a symlink, resulting in run-time errors like
that:
pg_rewind: error: file "pg_tblspc/NN" is of different type in source and target

In-place tablespaces are directories located in pg_tblspc/, returned as
relative paths instead of absolute paths, so rely on that to make the
difference with a normal tablespace and an in-place one.  If the path is
relative, the tablespace is handled as a directory.  If the path is
absolute, consider it as a symlink.

In-place tablespaces are only intended for development purposes, so like
363e8f9 no backpatch is done.  A test is added in pg_rewind with an
in-place tablespace and some data in it.

Author: Rui Zhao, Michael Paquier
Discussion: https://postgr.es/m/[email protected]

1 files changed, 10 insertions, 1 deletions

diff --git a/src/bin/pg_rewind/libpq_source.c b/src/bin/pg_rewind/libpq_source.c
index 0d8e9ee2d1a..417c74cfefc 100644
--- a/src/bin/pg_rewind/libpq_source.c
+++ b/src/bin/pg_rewind/libpq_source.c
@@ -298,7 +298,16 @@ libpq_traverse_files(rewind_source *source, process_file_callback_t callback)
 		link_target = PQgetvalue(res, i, 3);
 
 		if (link_target[0])
-			type = FILE_TYPE_SYMLINK;
+		{
+			/*
+			 * In-place tablespaces are directories located in pg_tblspc/ with
+			 * relative paths.
+			 */
+			if (is_absolute_path(link_target))
+				type = FILE_TYPE_SYMLINK;
+			else
+				type = FILE_TYPE_DIRECTORY;
+		}
 		else if (isdir)
 			type = FILE_TYPE_DIRECTORY;
 		else