From b47176e6a8b202380cb11fa3d0b2fd7331ead029 Mon Sep 17 00:00:00 2001
From: Andrew Ayer <agwa@andrewayer.name>
Date: Sat, 26 Dec 2015 13:01:35 -0800
Subject: [PATCH] Don't hard code path to git-crypt in .git/config on Linux

There's a tradeoff.  When the path is hardcoded, it's guaranteed that
git-crypt will be found no matter where you run git or what your $PATH is.
On the other hand, hardcoding means that things break if git-crypt changes
location, which could easily happen if you copy a repository to a different system
(see https://github.com/AGWA/git-crypt/issues/71 for example).

In hindsight, I think this was a bad tradeoff.  Now, if git-crypt is
invoked as a bare filename (no slashes), the bare filename is placed
in .git/config under the assumption that it can be found via $PATH
(this assumption will be true as long as git-crypt wasn't resolved via
a relative path in $PATH).  This logic was already being used on
non-Linux OSes and it seemed to work fine.
---
 util-unix.cpp | 44 ++++++++++++--------------------------------
 1 file changed, 12 insertions(+), 32 deletions(-)

diff --git a/util-unix.cpp b/util-unix.cpp
index 7c7c05b..6bea324 100644
--- a/util-unix.cpp
+++ b/util-unix.cpp
@@ -125,40 +125,20 @@ void	mkdir_parent (const std::string& path)
 	}
 }
 
-static std::string readlink (const char* pathname)
-{
-	std::vector<char>	buffer(64);
-	ssize_t			len;
-
-	while ((len = ::readlink(pathname, &buffer[0], buffer.size())) == static_cast<ssize_t>(buffer.size())) {
-		// buffer may have been truncated - grow and try again
-		buffer.resize(buffer.size() * 2);
-	}
-	if (len == -1) {
-		throw System_error("readlink", pathname, errno);
-	}
-
-	return std::string(buffer.begin(), buffer.begin() + len);
-}
-
 std::string our_exe_path ()
 {
-	try {
-		return readlink("/proc/self/exe");
-	} catch (const System_error&) {
-		if (argv0[0] == '/') {
-			// argv[0] starts with / => it's an absolute path
-			return argv0;
-		} else if (std::strchr(argv0, '/')) {
-			// argv[0] contains / => it a relative path that should be resolved
-			char*		resolved_path_p = realpath(argv0, NULL);
-			std::string	resolved_path(resolved_path_p);
-			free(resolved_path_p);
-			return resolved_path;
-		} else {
-			// argv[0] is just a bare filename => not much we can do
-			return argv0;
-		}
+	if (argv0[0] == '/') {
+		// argv[0] starts with / => it's an absolute path
+		return argv0;
+	} else if (std::strchr(argv0, '/')) {
+		// argv[0] contains / => it a relative path that should be resolved
+		char*		resolved_path_p = realpath(argv0, NULL);
+		std::string	resolved_path(resolved_path_p);
+		free(resolved_path_p);
+		return resolved_path;
+	} else {
+		// argv[0] is just a bare filename => not much we can do
+		return argv0;
 	}
 }