win32: extend normalisation of paths in realpath(3)

The code to normalise paths in resolve_symlinks(), which is used
by realpath(3), was incomplete and unable to handle UNC paths.
Make an ASCII version of normalize_ntpath() to extend the cases
covered.

This fixes a regression introduced by commit 585d17d26 (win32:
canonicalize path in chdir(2)):  it wasn't possible to change
to a directory with a UNC path.

1 files changed, 20 insertions, 2 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index b1a8b9711..44356d6b0 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1001,6 +1001,25 @@ int link(const char *oldpath, const char *newpath)
         return 0;
 }
 
+static char *normalize_ntpathA(char *buf)
+{
+        /* fix absolute path prefixes */
+        if (buf[0] == '\\') {
+                /* strip NT namespace prefixes */
+                if (!strncmp(buf, "\\??\\", 4) ||
+                    !strncmp(buf, "\\\\?\\", 4))
+                        buf += 4;
+                else if (!strncasecmp(buf, "\\DosDevices\\", 12))
+                        buf += 12;
+                /* replace remaining '...UNC\' with '\\' */
+                if (!strncasecmp(buf, "UNC\\", 4)) {
+                        buf += 2;
+                        *buf = '\\';
+                }
+        }
+        return buf;
+}
+
 static char *resolve_symlinks(char *path)
 {
         HANDLE h;
@@ -1022,8 +1041,7 @@ static char *resolve_symlinks(char *path)
                 status = GetFinalPathNameByHandleA(h, path, MAX_PATH,
                                                         FILE_NAME_NORMALIZED|VOLUME_NAME_DOS);
                 if (status != 0 && status < MAX_PATH) {
-                        /* skip '\\?\' prefix */
-                        ptr = (!strncmp(path, "\\\\?\\", 4)) ? (path + 4) : path;
+                        ptr = normalize_ntpathA(path);
                         goto end;
                 }
         }