1 files changed, 44 insertions, 0 deletions
diff --git a/compat/basename.c b/compat/basename.c
index 0f1b0b0930..96bd9533b4 100644
--- a/compat/basename.c
+++ b/compat/basename.c
@@ -1,4 +1,5 @@
 #include "../git-compat-util.h"
+#include "../strbuf.h"
 
 /* Adapted from libiberty's basename.c.  */
 char *gitbasename (char *path)
@@ -25,3 +26,46 @@ char *gitbasename (char *path)
 	}
 	return (char *)base;
 }
+
+char *gitdirname(char *path)
+{
+	static struct strbuf buf = STRBUF_INIT;
+	char *p = path, *slash = NULL, c;
+	int dos_drive_prefix;
+
+	if (!p)
+		return ".";
+
+	if ((dos_drive_prefix = skip_dos_drive_prefix(&p)) && !*p)
+		goto dot;
+
+	/*
+	 * POSIX.1-2001 says dirname("/") should return "/", and dirname("//")
+	 * should return "//", but dirname("///") should return "/" again.
+	 */
+	if (is_dir_sep(*p)) {
+		if (!p[1] || (is_dir_sep(p[1]) && !p[2]))
+			return path;
+		slash = ++p;
+	}
+	while ((c = *(p++)))
+		if (is_dir_sep(c)) {
+			char *tentative = p - 1;
+
+			/* POSIX.1-2001 says to ignore trailing slashes */
+			while (is_dir_sep(*p))
+				p++;
+			if (*p)
+				slash = tentative;
+		}
+
+	if (slash) {
+		*slash = '\0';
+		return path;
+	}
+
+dot:
+	strbuf_reset(&buf);
+	strbuf_addf(&buf, "%.*s.", dos_drive_prefix, path);
+	return buf.buf;
+}