duperemove: register the hashfile in the exclusion list

If the hashfile is stored in the dataset, then every run will
need to rescan the hashfile itself, with no chance of deduplication.

Fixes #335

Signed-off-by: Alexandre Bruyelles <git@jack.fr.eu.org>

duperemove.c

@@ -441,6 +441,20 @@ static int parse_options(int argc, char **argv, int *filelist_idx)
 	else if (update_hashes)
 		use_hashfile = H_UPDATE;
 
+	/*
+	 * Always add the hashfile and its wal etc to the exclude list
+	 * A wildcard would be easier but may exclude extra files silently,
+	 * this would be confusing for the user.
+	 */
+	if (options.hashfile != NULL) {
+		char tmp[PATH_MAX + 10 ] = {0,};
+		add_exclude_pattern(options.hashfile);
+		snprintf(tmp, PATH_MAX + 9, "%s-wal", options.hashfile);
+		add_exclude_pattern(tmp);
+		snprintf(tmp, PATH_MAX + 9, "%s-shm", options.hashfile);
+		add_exclude_pattern(tmp);
+	}
+
 	if (read_hashes) {
 		if (numfiles) {
 			eprintf("Error: --read-hashes option does not take a "