Fix access to uninitalized variables in GCC

Author: knizhnik

src/backend/storage/file/cfs.c

@@ -559,6 +559,8 @@ static bool cfs_gc_file(char* map_path)
 						close(md2);
 						md2 = -1;
 						newSize = pg_atomic_read_u32(&newMap->usedSize);
+						virtSize = pg_atomic_read_u32(&newMap->virtSize);
+						n_pages = virtSize / BLCKSZ;
 						remove_backups = false;
 						goto ReplaceMap;
 					}

src/backend/storage/smgr/md.c

@@ -502,12 +502,15 @@ mdunlinkfork(RelFileNodeBackend rnode, ForkNumber forkNum, bool isRedo)
 		if (md_use_compression(rnode, forkNum))
 		{
 			File file = PathNameOpenFile(path, O_RDWR | PG_BINARY | PG_COMPRESSION, 0);
+			ret = -1;
 			if (file >= 0) {
 				elog(LOG, "Truncate file %s", path);
 				if (FileTruncate(file, 0) < 0) { 
 					ereport(WARNING,
 							(errcode_for_file_access(),
 							 errmsg("could not truncate file \"%s\": %m", path)));
+				} else { 
+					ret = 0;
 				}
 			}
 			FileClose(file);