strbuf_readlink: support link targets that exceed PATH_MAX

kblees · dscho · commit 865ab35f1e67 · 2022-12-06T08:10:09.000+01:00
strbuf_readlink() refuses to read link targets that exceed PATH_MAX (even
if a sufficient size was specified by the caller).

As some platforms support longer paths, remove this restriction (similar
to strbuf_getcwd()).

Signed-off-by: Karsten Blees &lt;blees@dcon.de&gt;
diff --git a/strbuf.c b/strbuf.c
@@ -559,16 +559,14 @@ ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 	return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 }
 
-#define STRBUF_MAXLINK (2*PATH_MAX)
-
 int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 {
 	size_t oldalloc = sb->alloc;
 
 	if (hint < 32)
 		hint = 32;
 
-	while (hint < STRBUF_MAXLINK) {
+	for (;;) {
 		ssize_t len;
 
 		strbuf_grow(sb, hint + 1);

Original file line number	Diff line number	Diff line change
`@@ -559,16 +559,14 @@ ssize_t strbuf_write(struct strbuf sb, FILE f)`
`559`	`559`	`return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;`
`560`	`560`	`}`
`561`	`561`
`562`		`-#define STRBUF_MAXLINK (2*PATH_MAX)`
`563`		`-`
`564`	`562`	`int strbuf_readlink(struct strbuf sb, const char path, size_t hint)`
`565`	`563`	`{`
`566`	`564`	`size_t oldalloc = sb->alloc;`
`567`	`565`
`568`	`566`	`if (hint < 32)`
`569`	`567`	`hint = 32;`
`570`	`568`
`571`		`- while (hint < STRBUF_MAXLINK) {`
	`569`	`+ for (;;) {`
`572`	`570`	`ssize_t len;`
`573`	`571`
`574`	`572`	`strbuf_grow(sb, hint + 1);`