Allow add_path() to add non-existent directories to the path

This function had used make_absolute_path(); but this function dies if
the directory that contains the entry whose relative path was supplied in
the argument does not exist. This is a problem if the argument is, for
example, "../libexec/git-core", and that "../libexec" does not exist.

Since the resolution of symbolic links is not required for elements in
PATH, we can fall back to using make_nonrelative_path(), which simply
prepends $PWD to the path.

We have to move make_nonrelative_path() alongside make_absolute_path() in
abspath.c so that git-shell can be linked. See 5b8e6f85f.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

abspath.c

@@ -66,3 +66,39 @@ const char *make_absolute_path(const char *path)
 
 	return buf;
 }
+
+static const char *get_pwd_cwd(void)
+{
+	static char cwd[PATH_MAX + 1];
+	char *pwd;
+	struct stat cwd_stat, pwd_stat;
+	if (getcwd(cwd, PATH_MAX) == NULL)
+		return NULL;
+	pwd = getenv("PWD");
+	if (pwd && strcmp(pwd, cwd)) {
+		stat(cwd, &cwd_stat);
+		if (!stat(pwd, &pwd_stat) &&
+		    pwd_stat.st_dev == cwd_stat.st_dev &&
+		    pwd_stat.st_ino == cwd_stat.st_ino) {
+			strlcpy(cwd, pwd, PATH_MAX);
+		}
+	}
+	return cwd;
+}
+
+const char *make_nonrelative_path(const char *path)
+{
+	static char buf[PATH_MAX + 1];
+
+	if (is_absolute_path(path)) {
+		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+			die("Too long path: %.*s", 60, path);
+	} else {
+		const char *cwd = get_pwd_cwd();
+		if (!cwd)
+			die("Cannot determine the current working directory");
+		if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
+			die("Too long path: %.*s", 60, path);
+	}
+	return buf;
+}

exec_cmd.c

@@ -50,7 +50,7 @@ static void add_path(struct strbuf *out, const char *path)
 		if (is_absolute_path(path))
 			strbuf_addstr(out, path);
 		else
-			strbuf_addstr(out, make_absolute_path(path));
+			strbuf_addstr(out, make_nonrelative_path(path));
 
 		strbuf_addch(out, PATH_SEP);
 	}

path.c

@@ -291,42 +291,6 @@ int adjust_shared_perm(const char *path)
 	return 0;
 }
 
-static const char *get_pwd_cwd(void)
-{
-	static char cwd[PATH_MAX + 1];
-	char *pwd;
-	struct stat cwd_stat, pwd_stat;
-	if (getcwd(cwd, PATH_MAX) == NULL)
-		return NULL;
-	pwd = getenv("PWD");
-	if (pwd && strcmp(pwd, cwd)) {
-		stat(cwd, &cwd_stat);
-		if (!stat(pwd, &pwd_stat) &&
-		    pwd_stat.st_dev == cwd_stat.st_dev &&
-		    pwd_stat.st_ino == cwd_stat.st_ino) {
-			strlcpy(cwd, pwd, PATH_MAX);
-		}
-	}
-	return cwd;
-}
-
-const char *make_nonrelative_path(const char *path)
-{
-	static char buf[PATH_MAX + 1];
-
-	if (is_absolute_path(path)) {
-		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
-			die ("Too long path: %.*s", 60, path);
-	} else {
-		const char *cwd = get_pwd_cwd();
-		if (!cwd)
-			die("Cannot determine the current working directory");
-		if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
-			die ("Too long path: %.*s", 60, path);
-	}
-	return buf;
-}
-
 const char *make_relative_path(const char *abs, const char *base)
 {
 	static char buf[PATH_MAX + 1];