Cygwin: use locale-aware conversion to UNICODE_STRING checking mount points

mount_info::get_mounts_here used RtlCreateUnicodeStringFromAsciiz
which translates bytes into wide chars verbatim.

Create a new function sys_mbstouni_alloc which can be used from
mount_info::get_mounts_here to convert multibyte mount point
strings to UNICODE_STRINGS in a locale-aware way.

For symmetry, create a function mount_info::free_mounts_here,
so the knwoledge how to free the UNICODE_STRING buffers is
encapsulated in the same class.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/fhandler_disk_file.cc

@@ -40,7 +40,7 @@ class __DIR_mounts
 {
   int		 count;
   const char	*parent_dir;
-  int		 parent_dir_len;
+  size_t	 parent_dir_len;
   UNICODE_STRING mounts[MAX_MOUNTS];
   bool		 found[MAX_MOUNTS + 3];
   UNICODE_STRING cygdrive;
@@ -60,9 +60,7 @@ public:
     }
   ~__DIR_mounts ()
     {
-      for (int i = 0; i < count; ++i)
-	RtlFreeUnicodeString (&mounts[i]);
-      RtlFreeUnicodeString (&cygdrive);
+      mount_table->free_mounts_here (mounts, count, &cygdrive);
     }
   /* For an entry within this dir, check if a mount point exists. */
   bool check_mount (PUNICODE_STRING fname)

winsup/cygwin/mount.cc

@@ -723,12 +723,12 @@ mount_info::conv_to_win32_path (const char *src_path, char *dst, device& dev,
   return rc;
 }
 
-int
-mount_info::get_mounts_here (const char *parent_dir, int parent_dir_len,
+size_t
+mount_info::get_mounts_here (const char *parent_dir, size_t parent_dir_len,
 			     PUNICODE_STRING mount_points,
 			     PUNICODE_STRING cygd)
 {
-  int n_mounts = 0;
+  size_t n_mounts = 0;
 
   for (int i = 0; i < nmounts; i++)
     {
@@ -739,20 +739,29 @@ mount_info::get_mounts_here (const char *parent_dir, int parent_dir_len,
       if (last_slash == mi->posix_path)
 	{
 	  if (parent_dir_len == 1 && mi->posix_pathlen > 1)
-	    RtlCreateUnicodeStringFromAsciiz (&mount_points[n_mounts++],
-					      last_slash + 1);
+	    sys_mbstouni_alloc (&mount_points[n_mounts++], HEAP_NOTHEAP,
+			        last_slash + 1);
 	}
-      else if (parent_dir_len == last_slash - mi->posix_path
+      else if (parent_dir_len == (size_t) (last_slash - mi->posix_path)
 	       && strncasematch (parent_dir, mi->posix_path, parent_dir_len))
-	RtlCreateUnicodeStringFromAsciiz (&mount_points[n_mounts++],
-					  last_slash + 1);
+	sys_mbstouni_alloc (&mount_points[n_mounts++], HEAP_NOTHEAP,
+			    last_slash + 1);
     }
-  RtlCreateUnicodeStringFromAsciiz (cygd, cygdrive + 1);
+  sys_mbstouni_alloc (cygd, HEAP_NOTHEAP, cygdrive + 1);
   if (cygd->Length)
     cygd->Length -= 2;	// Strip trailing slash
   return n_mounts;
 }
 
+void
+mount_info::free_mounts_here (PUNICODE_STRING mount_points, int n_mounts,
+			      PUNICODE_STRING cygd)
+{
+  for (int i = 0; i < n_mounts; ++i)
+    free (mount_points[i].Buffer);
+  free (cygd->Buffer);
+}
+
 /* cygdrive_posix_path: Build POSIX path used as the
    mount point for cygdrives created when there is no other way to
    obtain a POSIX path from a Win32 one.

winsup/cygwin/mount.h

@@ -199,9 +199,11 @@ class mount_info
   int get_cygdrive_info (char *user, char *system, char* user_flags,
 			 char* system_flags);
   void cygdrive_posix_path (const char *src, char *dst, int flags);
-  int get_mounts_here (const char *parent_dir, int,
-		       PUNICODE_STRING mount_points,
-		       PUNICODE_STRING cygd);
+  size_t get_mounts_here (const char *parent_dir, size_t,
+			  PUNICODE_STRING mount_points,
+			  PUNICODE_STRING cygd);
+  void free_mounts_here (PUNICODE_STRING, int, PUNICODE_STRING);
+
 
  private:
   void sort ();

winsup/cygwin/wchar.h

@@ -91,6 +91,16 @@ sys_mbstowcs (wchar_t * dst, size_t dlen, const char *src,
 
 size_t sys_mbstowcs_alloc (wchar_t **, int, const char *, size_t = (size_t) -1);
 
+static inline size_t
+sys_mbstouni_alloc (PUNICODE_STRING dst, int type, const char *src,
+		    size_t nms = (size_t) -1)
+{
+  size_t len = sys_mbstowcs_alloc (&dst->Buffer, type, src, nms);
+  dst->MaximumLength = len * sizeof (WCHAR);
+  dst->Length = dst->MaximumLength - sizeof (WCHAR);
+  return dst->MaximumLength;
+}
+
 #endif /* __cplusplus */
 #endif /* __INSIDE_CYGWIN__ */