From bd47dce95fb1395e613d61aa9af737d178c7ba95 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Tue, 18 Apr 2017 12:09:08 +0200
Subject: [PATCH 1/2] mingw: demonstrate a problem with certain absolute paths

On Windows, there are several categories of absolute paths. One such
category starts with a backslash and is implicitly relative to the
drive associated with the current working directory. Example:

	c:
	git clone https://github.com/git-for-windows/git \G4W

should clone into C:\G4W.

There is currently a problem with that, in that mingw_mktemp() does not
expect the _wmktemp() function to prefix the absolute path with the
drive prefix, and as a consequence, the resulting path does not fit into
the originally-passed string buffer. The symptom is a "Result too large"
error.

Reported by Juan Carlos Arevalo Baeza.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t5580-clone-push-unc.sh | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/t/t5580-clone-push-unc.sh b/t/t5580-clone-push-unc.sh
index b322c2f72202fb..42867b56b02b30 100755
--- a/t/t5580-clone-push-unc.sh
+++ b/t/t5580-clone-push-unc.sh
@@ -11,14 +11,11 @@ fi
 UNCPATH="$(pwd)"
 case "$UNCPATH" in
 [A-Z]:*)
+	WITHOUTDRIVE="${UNCPATH#?:}"
 	# Use administrative share e.g. \\localhost\C$\git-sdk-64\usr\src\git
 	# (we use forward slashes here because MSYS2 and Git accept them, and
 	# they are easier on the eyes)
-	UNCPATH="//localhost/${UNCPATH%%:*}\$/${UNCPATH#?:}"
-	test -d "$UNCPATH" || {
-		skip_all='could not access administrative share; skipping'
-		test_done
-	}
+	UNCPATH="//localhost/${UNCPATH%%:*}\$$WITHOUTDRIVE"
 	;;
 *)
 	skip_all='skipping UNC path tests, cannot determine current path as UNC'
@@ -26,6 +23,18 @@ case "$UNCPATH" in
 	;;
 esac
 
+test_expect_failure 'clone into absolute path lacking a drive prefix' '
+	USINGBACKSLASHES="$(echo "$WITHOUTDRIVE"/without-drive-prefix |
+		tr / \\)" &&
+	git clone . "$USINGBACKSLASHES" &&
+	test -f without-drive-prefix/.git/HEAD
+'
+
+test -d "$UNCPATH" || {
+	skip_all='could not access administrative share; skipping'
+	test_done
+}
+
 test_expect_success setup '
 	test_commit initial
 '

From 4b604ca0c97ab6ea2848f946fe0438643911fa6d Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Tue, 18 Apr 2017 12:38:30 +0200
Subject: [PATCH 2/2] mingw: allow absolute paths without drive prefix

When specifying an absolute path without a drive prefix, we convert that
path internally. Let's make sure that we handle that case properly, too
;-)

This fixes the command

	git clone https://github.com/git-for-windows/git \G4W

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/mingw.c            | 10 +++++++++-
 t/t5580-clone-push-unc.sh |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index 9a35a43391c12e..abf266d92bec91 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -806,12 +806,20 @@ unsigned int sleep (unsigned int seconds)
 char *mingw_mktemp(char *template)
 {
 	wchar_t wtemplate[MAX_PATH];
+	int offset = 0;
+
 	/* we need to return the path, thus no long paths here! */
 	if (xutftowcs_path(wtemplate, template) < 0)
 		return NULL;
+
+	if (is_dir_sep(template[0]) && !is_dir_sep(template[1]) &&
+	    iswalpha(wtemplate[0]) && wtemplate[1] == L':') {
+		/* We have an absolute path missing the drive prefix */
+		offset = 2;
+	}
 	if (!_wmktemp(wtemplate))
 		return NULL;
-	if (xwcstoutf(template, wtemplate, strlen(template) + 1) < 0)
+	if (xwcstoutf(template, wtemplate + offset, strlen(template) + 1) < 0)
 		return NULL;
 	return template;
 }
diff --git a/t/t5580-clone-push-unc.sh b/t/t5580-clone-push-unc.sh
index 42867b56b02b30..a137d832c3bd00 100755
--- a/t/t5580-clone-push-unc.sh
+++ b/t/t5580-clone-push-unc.sh
@@ -23,7 +23,7 @@ case "$UNCPATH" in
 	;;
 esac
 
-test_expect_failure 'clone into absolute path lacking a drive prefix' '
+test_expect_success 'clone into absolute path lacking a drive prefix' '
 	USINGBACKSLASHES="$(echo "$WITHOUTDRIVE"/without-drive-prefix |
 		tr / \\)" &&
 	git clone . "$USINGBACKSLASHES" &&