From 21f368daab677724ca1a200c22d65b64b15117b5 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 9 Jan 2026 20:05:08 +0000 Subject: [PATCH] strbuf_readlink(): support link targets that exceed 2*PATH_MAX The `strbuf_readlink()` function refuses to read link targets that exceed 2*PATH_MAX (even if a sufficient size was specified by the caller). The reason that that limit is 2*PATH_MAX instead of PATH_MAX is that the symlink targets do not need to be normalized. After running `ln -s a/../a/../a/../a/../b c`, the target of the symlink `c` will not be normalized to `b` but instead be much longer. As such, symlink targets' lengths can far exceed PATH_MAX. They are frequently much longer than 2*PATH_MAX on Windows, which actually supports paths up to 32,767 characters, but sets PATH_MAX to 260 for backwards compatibility. For full details, see https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation Let's just hard-code the limit used by `strbuf_readlink()` to 32,767 and make it independent of the current platform's PATH_MAX. Based-on-a-patch-by: Karsten Blees Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- strbuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/strbuf.c b/strbuf.c index 44a8f6a554..ec2b7afbe6 100644 --- a/strbuf.c +++ b/strbuf.c @@ -566,7 +566,7 @@ 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) +#define STRBUF_MAXLINK (32767) int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) {