fixup! filename: add is_escapable function

src/core/opamFilename.ml

@@ -9,15 +9,9 @@
 (*                                                                        *)
 (**************************************************************************)
 
-let is_escapable =
-  let re =
-    Re.(compile @@ seq [
-        alt [ char '/'; char '\\'];
-        str "..";
-        alt [ char '/'; char '\\']
-      ])
-  in
-  fun s -> Re.matches re s <> []
+let might_escape path =
+  List.exists (String.equal Filename.parent_dir_name)
+    Re.(split (compile (str Filename.dir_sep)) path)
 
 module Base = struct
   include OpamStd.AbstractString

src/core/opamFilename.mli

@@ -12,8 +12,8 @@
 (** Higher level file and directory name manipulation AND file operations,
     wrappers on OpamSystem using the filename type *)
 
-(* Returns [true] if string contains '/../' or '\..\' *)
-val is_escapable: string -> bool
+(* Returns [true] if string contains '..' between directory separators *)
+val might_escape: string -> bool
 
 (** Basenames *)
 module Base: sig