Merge branch 'js/dirname-basename' into maint

dirname() emulation has been added, as Msys2 lacks it.

* js/dirname-basename:
  mingw: avoid linking to the C library's isalpha()
  t0060: loosen overly strict expectations
  t0060: verify that basename() and dirname() work as expected
  compat/basename.c: provide a dirname() compatibility function
  compat/basename: make basename() conform to POSIX
  Refactor skipping DOS drive prefixes

3 files changed, 77 insertions, 15 deletions

diff --git a/compat/basename.c b/compat/basename.c
index d8f8a3c6dc..96bd9533b4 100644
--- a/compat/basename.c
+++ b/compat/basename.c
@@ -1,15 +1,71 @@
 #include "../git-compat-util.h"
+#include "../strbuf.h"
 
 /* Adapted from libiberty's basename.c.  */
 char *gitbasename (char *path)
 {
 	const char *base;
-	/* Skip over the disk name in MSDOS pathnames. */
-	if (has_dos_drive_prefix(path))
-		path += 2;
+
+	if (path)
+		skip_dos_drive_prefix(&path);
+
+	if (!path || !*path)
+		return ".";
+
 	for (base = path; *path; path++) {
-		if (is_dir_sep(*path))
-			base = path + 1;
+		if (!is_dir_sep(*path))
+			continue;
+		do {
+			path++;
+		} while (is_dir_sep(*path));
+		if (*path)
+			base = path;
+		else
+			while (--path != base && is_dir_sep(*path))
+				*path = '\0';
 	}
 	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;
+}
diff --git a/compat/mingw.c b/compat/mingw.c
index 5edea29508..9b2a1f552e 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1932,28 +1932,31 @@ pid_t waitpid(pid_t pid, int *status, int options)
 	return -1;
 }
 
+int mingw_skip_dos_drive_prefix(char **path)
+{
+	int ret = has_dos_drive_prefix(*path);
+	*path += ret;
+	return ret;
+}
+
 int mingw_offset_1st_component(const char *path)
 {
-	int offset = 0;
-	if (has_dos_drive_prefix(path))
-		offset = 2;
+	char *pos = (char *)path;
 
 	/* unc paths */
-	else if (is_dir_sep(path[0]) && is_dir_sep(path[1])) {
-
+	if (!skip_dos_drive_prefix(&pos) &&
+			is_dir_sep(pos[0]) && is_dir_sep(pos[1])) {
 		/* skip server name */
-		char *pos = strpbrk(path + 2, "\\/");
+		pos = strpbrk(pos + 2, "\\/");
 		if (!pos)
 			return 0; /* Error: malformed unc path */
 
 		do {
 			pos++;
 		} while (*pos && !is_dir_sep(*pos));
-
-		offset = pos - path;
 	}
 
-	return offset + is_dir_sep(path[offset]);
+	return pos + is_dir_sep(*pos) - path;
 }
 
 int xutftowcsn(wchar_t *wcs, const char *utfs, size_t wcslen, int utflen)
diff --git a/compat/mingw.h b/compat/mingw.h
index 57ca477d1f..a5fb52f977 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -361,7 +361,10 @@ HANDLE winansi_get_osfhandle(int fd);
  * git specific compatibility
  */
 
-#define has_dos_drive_prefix(path) (isalpha(*(path)) && (path)[1] == ':')
+#define has_dos_drive_prefix(path) \
+	(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 is_dir_sep(c) ((c) == '/' || (c) == '\\')
 static inline char *mingw_find_last_dir_sep(const char *path)
 {