2 files changed, 38 insertions, 2 deletions
diff --git a/compat/win32/path-utils.c b/compat/win32/path-utils.c
index d9d3641de8..ebf2f12eb6 100644
--- a/compat/win32/path-utils.c
+++ b/compat/win32/path-utils.c
@@ -1,5 +1,29 @@
 #include "../../git-compat-util.h"
 
+int win32_has_dos_drive_prefix(const char *path)
+{
+	int i;
+
+	/*
+	 * Does it start with an ASCII letter (i.e. highest bit not set),
+	 * followed by a colon?
+	 */
+	if (!(0x80 & (unsigned char)*path))
+		return *path && path[1] == ':' ? 2 : 0;
+
+	/*
+	 * While drive letters must be letters of the English alphabet, it is
+	 * possible to assign virtually _any_ Unicode character via `subst` as
+	 * a drive letter to "virtual drives". Even `1`, or `ä`. Or fun stuff
+	 * like this:
+	 *
+	 *      subst ֍: %USERPROFILE%\Desktop
+	 */
+	for (i = 1; i < 4 && (0x80 & (unsigned char)path[i]); i++)
+		; /* skip first UTF-8 character */
+	return path[i] == ':' ? i + 1 : 0;
+}
+
 int win32_skip_dos_drive_prefix(char **path)
 {
 	int ret = has_dos_drive_prefix(*path);
diff --git a/compat/win32/path-utils.h b/compat/win32/path-utils.h
index 8ed062a6b7..bba2b64408 100644
--- a/compat/win32/path-utils.h
+++ b/compat/win32/path-utils.h
@@ -1,8 +1,9 @@
 #ifndef WIN32_PATH_UTILS_H
 #define WIN32_PATH_UTILS_H
 
-#define has_dos_drive_prefix(path) \
-	(isalpha(*(path)) && (path)[1] == ':' ? 2 : 0)
+int win32_has_dos_drive_prefix(const char *path);
+#define has_dos_drive_prefix win32_has_dos_drive_prefix
+
 int win32_skip_dos_drive_prefix(char **path);
 #define skip_dos_drive_prefix win32_skip_dos_drive_prefix
 static inline int win32_is_dir_sep(int c)
@@ -19,6 +20,17 @@ static inline char *win32_find_last_dir_sep(const char *path)
 	return ret;
 }
 #define find_last_dir_sep win32_find_last_dir_sep
+static inline int win32_has_dir_sep(const char *path)
+{
+	/*
+	 * See how long the non-separator part of the given path is, and
+	 * if and only if it covers the whole path (i.e. path[len] is NUL),
+	 * there is no separator in the path---otherwise there is a separator.
+	 */
+	size_t len = strcspn(path, "/\\");
+	return !!path[len];
+}
+#define has_dir_sep(path) win32_has_dir_sep(path)
 int win32_offset_1st_component(const char *path);
 #define offset_1st_component win32_offset_1st_component