File 0927-Fix-filelib-wildcard-1-2-for-not-a-directory.patch of Package erlang

From f7bc9fc284a46b906dba5c935628855adbc7a258 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 3 Jun 2020 13:29:24 +0200
Subject: [PATCH] Fix filelib:wildcard/1,2 for "not-a-directory/.."

---
 lib/stdlib/src/filelib.erl        | 38 +++++++++++++++++++++++++++----
 lib/stdlib/test/filelib_SUITE.erl |  2 ++
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/lib/stdlib/src/filelib.erl b/lib/stdlib/src/filelib.erl
index 565f00b0a5..7f8c282a79 100644
--- a/lib/stdlib/src/filelib.erl
+++ b/lib/stdlib/src/filelib.erl
@@ -268,9 +268,9 @@ do_wildcard(Pattern, Cwd, Mod) ->
     lists:sort(Files).
 
 do_wildcard_1({exists,File}, Mod) ->
-    case eval_read_link_info(File, Mod) of
-	{ok,_} -> [File];
-	_ -> []
+    case exists(File, Mod) of
+	true -> [File];
+	false -> []
     end;
 do_wildcard_1([Base|Rest], Mod) ->
     do_wildcard_2([Base], Rest, [], Mod).
@@ -562,6 +562,36 @@ wrap_escapes([]) ->
 badpattern(Reason) ->
     error({badpattern,Reason}).
 
+exists(File, Mod) ->
+    case eval_read_link_info(File, Mod) of
+        {error, _} ->
+            false;
+        {ok, _Info} ->
+            case os:type() of
+                {win32,_} ->
+                    do_exists(filename:split(File), Mod, []);
+                _ ->
+                    true
+            end
+    end.
+
+do_exists([P,".."|Ps], Mod, Acc) ->
+    %% On Windows, "pathname/.." will seem to exist even if pathname
+    %% does not refer to a directory.
+    Path = case Acc of
+               [] -> P;
+               _ -> filename:join(lists:reverse(Acc, [P]))
+           end,
+    case eval_read_link_info(Path, Mod) of
+        {ok, #file_info{type=directory}} ->
+            do_exists(Ps, Mod, Acc);
+        _ ->
+            false
+    end;
+do_exists([P|Ps], Mod, Acc) ->
+    do_exists(Ps, Mod, [P|Acc]);
+do_exists([], _, _) -> true.
+
 eval_read_file_info(File, file) ->
     file:read_file_info(File);
 eval_read_file_info(File, erl_prim_loader) ->
diff --git a/lib/stdlib/test/filelib_SUITE.erl b/lib/stdlib/test/filelib_SUITE.erl
index 367dd6b407..203ba2c31e 100644
--- a/lib/stdlib/test/filelib_SUITE.erl
+++ b/lib/stdlib/test/filelib_SUITE.erl
@@ -123,6 +123,8 @@ wcc(Wc, Error) ->
     {'EXIT',{{badpattern,Error},
 	     [{filelib,wildcard,2,_}|_]}} = (catch filelib:wildcard(Wc, ".")).
 
+disable_prefix_opt([_,$:|_]=Wc) ->
+    Wc;
 disable_prefix_opt([C|Wc]) when $a =< C, C =< $z; C =:= $@ ->
     %% There is an optimization for patterns that have a literal prefix
     %% (such as "lib/compiler/ebin/*"). Test that we'll get the same result
-- 
2.26.2