merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 19 insertions, 2 deletions

diff --git a/third_party/git/compat/win32/path-utils.h b/third_party/git/compat/win32/path-utils.h
index 0f70d439204f..bba2b644080f 100644
--- a/third_party/git/compat/win32/path-utils.h
+++ b/third_party/git/compat/win32/path-utils.h
@@ -1,5 +1,9 @@
-#define has_dos_drive_prefix(path) \
-	(isalpha(*(path)) && (path)[1] == ':' ? 2 : 0)
+#ifndef WIN32_PATH_UTILS_H
+#define WIN32_PATH_UTILS_H
+
+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)
@@ -16,5 +20,18 @@ 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
+
+#endif