From 313a35d009cd1ea5e60eec89a21f248ddb4b81d0 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mon, 31 Aug 2015 12:57:45 +0000
Subject: [PATCH] mingw: support UNC alternates

Just like we support having alternates pointing to different drives, we
want to support alternates pointing to network shares, i.e. UNC paths.

Technically, what we do in this patch is not to support UNC alternates,
but to support UNC paths when normalizing paths. But the latter implies
the former, and the former really was the motivation for this patch.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/mingw.h    | 1 +
 git-compat-util.h | 8 ++++++++
 path.c            | 4 ++--
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/compat/mingw.h b/compat/mingw.h
index 1de70ffd62a630..bd242e493853c8 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -387,6 +387,7 @@ HANDLE winansi_get_osfhandle(int fd);
 	(isalpha(*(path)) && (path)[1] == ':' ? 2 : 0)
 int mingw_skip_dos_drive_prefix(char **path);
 #define skip_dos_drive_prefix mingw_skip_dos_drive_prefix
+#define has_unc_prefix(path) (*(path) == '\\' && (path)[1] == '\\' ? 2 : 0)
 #define is_dir_sep(c) ((c) == '/' || (c) == '\\')
 static inline char *mingw_find_last_dir_sep(const char *path)
 {
diff --git a/git-compat-util.h b/git-compat-util.h
index 474395471f623d..f1b5c20c2b33b1 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -349,6 +349,14 @@ static inline int git_skip_dos_drive_prefix(char **path)
 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 #endif
 
+#ifndef has_unc_prefix
+static inline int git_has_unc_prefix(const char *path)
+{
+	return 0;
+}
+#define has_unc_prefix git_has_unc_prefix
+#endif
+
 #ifndef is_dir_sep
 static inline int git_is_dir_sep(int c)
 {
diff --git a/path.c b/path.c
index 969b494d72dff1..d0bde482696e77 100644
--- a/path.c
+++ b/path.c
@@ -943,9 +943,9 @@ const char *remove_leading_path(const char *in, const char *prefix)
 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
 {
 	char *dst0;
-	int i;
+	int i = has_unc_prefix(src);
 
-	for (i = has_dos_drive_prefix(src); i > 0; i--)
+	for (i = i ? i : has_dos_drive_prefix(src); i > 0; i--)
 		*dst++ = *src++;
 	dst0 = dst;