From: Philip Hazelden <philip.hazelden@gmail.com>
Date: Sun, 3 Jul 2022 17:54:43 +0000 (+0100)
Subject: Fix `rename -a ''`.
X-Git-Tag: v2.39-rc1~584^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2285629d7d4564773b106fa1fa29a3e34cbed3ea;p=thirdparty%2Futil-linux.git

Fix `rename -a ''`.

It previously entered an infinite loop. Now it inserts the `to` string
between every character of `from`, including at the beginning and end.

    rename -a '' _ 123.txt # renames to _1_2_3_._t_x_t_
---

diff --git a/misc-utils/rename.c b/misc-utils/rename.c
index e47359c0d9..80a0f31ca4 100644
--- a/misc-utils/rename.c
+++ b/misc-utils/rename.c
@@ -57,8 +57,8 @@ static int string_replace(char *from, char *to, char *s, char *orig, char **newn
 	if (where == NULL)
 		return 1;
 	count++;
-	while ((all || last) && p) {
-		p = strstr(p + (last ? 1 : fromlen), from);
+	while ((all || last) && p && *p) {
+		p = strstr(p + (last ? 1 : max(fromlen, (size_t) 1)), from);
 		if (p) {
 			if (all)
 				count++;
@@ -75,8 +75,13 @@ static int string_replace(char *from, char *to, char *s, char *orig, char **newn
 		p = to;
 		while (*p)
 			*q++ = *p++;
-		p = where + fromlen;
-		where = strstr(p, from);
+		if (fromlen > 0) {
+			p = where + fromlen;
+			where = strstr(p, from);
+		} else {
+			p = where;
+			where += 1;
+		}
 	}
 	while (*p)
 		*q++ = *p++;
diff --git a/tests/expected/rename/basic b/tests/expected/rename/basic
index 4a1809828d..2712ba14b7 100644
--- a/tests/expected/rename/basic
+++ b/tests/expected/rename/basic
@@ -16,3 +16,4 @@ what is rename_all* *.? doing here?
 `rename_zz_last_zzz.y' -> `rename_zz_last_zAAzzBB.y'
 `rename_zz_last_zzz.z' -> `rename_zz_last_zAAzzBB.z'
 what is rename*last* doing here?
+`rename_all_empty' -> `_r_e_n_a_m_e___a_l_l___e_m_p_t_y_'
diff --git a/tests/ts/rename/basic b/tests/ts/rename/basic
index fb20b49dd3..83ed5a05d7 100755
--- a/tests/ts/rename/basic
+++ b/tests/ts/rename/basic
@@ -68,4 +68,8 @@ for i in rename*last* ; do
 	echo "what is $i doing here?" >> $TS_OUTPUT
 done
 
+touch rename_all_empty
+$TS_CMD_RENAME -v -a '' _ rename_all_empty >> $TS_OUTPUT 2>> $TS_ERRLOG
+rm -f _r_e_n_a_m_e___a_l_l___e_m_p_t_y_
+
 ts_finalize