Subject: [PATCH v5 0/5] road to reentrant real_path

From: Brandon Williams <[email-masked]>
Date: Wed, 4 Jan 2017 14:01:19 -0800

changes in v5:
* set errno to ELOOP when MAXSYMLINKS is exceded.
* revert to use MAXSYMLINKS instead of MAXDEPTH.
* If the OS hasn't defined MAXSYMLINKS, use a fallback value of 32.

Brandon Williams (4):
  real_path: resolve symlinks by hand
  real_path: convert real_path_internal to strbuf_realpath
  real_path: create real_pathdup
  real_path: have callers use real_pathdup and strbuf_realpath

Johannes Sixt (1):
  real_path: canonicalize directory separators in root parts

 abspath.c         | 231 +++++++++++++++++++++++++++++++++++++-----------------
 builtin/init-db.c |   6 +-
 cache.h           |   3 +
 environment.c     |   2 +-
 setup.c           |  13 +--
 sha1_file.c       |   2 +-
 submodule.c       |   2 +-
 transport.c       |   2 +-
 worktree.c        |   2 +-
 9 files changed, 178 insertions(+), 85 deletions(-)

--- interdiff with v4

diff --git a/abspath.c b/abspath.c
index 3562d17bf..fce40fddc 100644
--- a/abspath.c
+++ b/abspath.c
@@ -62,7 +62,9 @@ static void get_root_part(struct strbuf *resolved, struct strbuf *remaining)
 }
 
 /* We allow "recursive" symbolic links. Only within reason, though. */
-#define MAXDEPTH 5
+#ifndef MAXSYMLINKS
+#define MAXSYMLINKS 32
+#endif
 
 /*
  * Return the real path (i.e., absolute path, with symlinks resolved
@@ -138,10 +140,12 @@ char *strbuf_realpath(struct strbuf *resolved, const char *path,
 			ssize_t len;
 			strbuf_reset(&symlink);
 
-			if (num_symlinks++ > MAXDEPTH) {
+			if (num_symlinks++ > MAXSYMLINKS) {
+				errno = ELOOP;
+
 				if (die_on_error)
 					die("More than %d nested symlinks "
-					    "on path '%s'", MAXDEPTH, path);
+					    "on path '%s'", MAXSYMLINKS, path);
 				else
 					goto error_out;
 			}

-- 
2.11.0.390.gc69c2f50cf-goog