[Issue #66] fix segfault when restoring full backup, rewrite help

Author: gsmolk

src/data.c

@@ -1135,7 +1135,7 @@ restore_data_file_internal(FILE *in, FILE *out, pgFile *file, uint32 backup_vers
 			page_lsn = PageXLogRecPtrGet(phdr->pd_lsn);
 
 			/*
-			 * The heart of incremental restore
+			 * The heart of incremental restore in 'checksum' mode
 			 * If page in backup has the same checksum and lsn as
 			 * page in backup, then page can be skipped.
 			 */

src/help.c

@@ -433,7 +433,7 @@ help_restore(void)
 	printf(_("                                   relocate the external directory from OLDDIR to NEWDIR\n"));
 	printf(_("      --skip-external-dirs         do not restore all external directories\n"));
 	printf(_("  -I, --incremental-mode=none|checksum|lsn\n"));
-	printf(_("                                   reuse already existing unchanged valid pages in PGDATA\n"));
+	printf(_("                                   reuse valid pages available in PGDATA if they have not changed\n"));
 	printf(_("                                   (default: none)\n"));
 
 	printf(_("\n  Partial restore options:\n"));

src/restore.c

@@ -712,7 +712,7 @@ restore_chain(pgBackup *dest_backup, parray *parent_chain,
 	 */
 	if (use_bitmap && parray_num(parent_chain) == 1)
 	{
-		if (params->incremental_mode == INCR_NONE)
+		if (params->incremental_mode == INCR_LSN)
 			use_bitmap = true;
 		else
 			use_bitmap = false;