ash: match behaviour of cmd.exe in cd builtin

The Windows API strips trailing dots and spaces from the last
component of a path.  cmd.exe handles this quirk when changing
directory by adjusting its idea of the current directory to match
reality.  The shell in busybox-w32 didn't do this, leading to some
confusion.

Fix the shell's cd builtin so it works more like cmd.exe.

Adds 64-80 bytes.

(GitHub issue #478)

1 files changed, 13 insertions, 0 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index 87e7ca602..6842dba48 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -2178,6 +2178,19 @@ void FAST_FUNC slash_to_bs(char *p)
         }
 }
 
+/* Windows strips trailing dots and spaces from the last component of
+ * a file path.  This routine emulates that behaviour so we can preempt
+ * Windows if necessary. */
+void FAST_FUNC strip_dot_space(char *p)
+{
+        char *start = (char *)bb_basename(p);
+        char *end = start + strlen(start);
+
+        while (end > start && (end[-1] == '.' || end[-1] == ' ')) {
+                *--end = '\0';
+        }
+}
+
 size_t FAST_FUNC remove_cr(char *p, size_t len)
 {
         ssize_t i, j;