lib/54131: libedit: declaration of i inside for loop in unescape_string

[jperkins+netbsd%google.com@localhost]

>Number:         54131
>Category:       lib
>Synopsis:       libedit: declaration of i inside for loop in unescape_string
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Apr 19 22:35:00 +0000 2019
>Originator:     Jonathan Perkins
>Release:        Sources as of 2019/04/19
>Organization:
Google
>Environment:
>Description:
In filecomplete.c, unescape_string has a declaration inside a for loop.  This is incompatible with certain C versions.

The specific line in unescape_string that's an issue is:
	for (size_t i = 0; i < length ; i++) {

This was added in revision 53 (http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libedit/filecomplete.c.diff?r1=1.52&r2=1.53&only_with_tag=MAIN&f=h)

This just looked like an oversight to me because most of the code declares outside the for loop.  I noticed because we have some code that compiles in a way that hit the issue.
>How-To-Repeat:
gcc -std=c90 -c filecomplete.c -o filecomplete.o
>Fix:
--- old/src/lib/libedit/filecomplete.c
+++ new/src/lib/libedit/filecomplete.c
@@ -193,8 +193,8 @@ unescape_string(const wchar_t *string, s
 	wchar_t *unescaped = el_malloc(sizeof(*string) * (length + 1));
 	if (unescaped == NULL)
 		return NULL;
-	size_t j = 0;
-	for (size_t i = 0; i < length ; i++) {
+	size_t i = 0, j = 0;
+	for (; i < length ; i++) {
 		if (string[i] == '\\')
 			continue;
 		unescaped[j++] = string[i];