From 79648648407f20fe78a2740074101c76259bb138 Mon Sep 17 00:00:00 2001
From: Mikael Pettersson <mikpelinux@gmail.com>
Date: Mon, 16 Mar 2020 21:27:37 +0100
Subject: [PATCH] getopt: an argument inexactly matching two different but
 equivalent options is considered a match

---
 erlang/apps/lib/src/getopt.erl | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/erlang/apps/lib/src/getopt.erl b/erlang/apps/lib/src/getopt.erl
index 848f68e..3078623 100644
--- a/erlang/apps/lib/src/getopt.erl
+++ b/erlang/apps/lib/src/getopt.erl
@@ -172,11 +172,18 @@ find_longopt(Prefix, [Option = {Name, _HasArg, _Val} | LongOpts], IsSingleDash,
   case longopt_prefix(Name, Prefix, IsSingleDash) of
     nomatch -> find_longopt(Prefix, LongOpts, IsSingleDash, Candidate);
     [] -> Option;
-    _ when Candidate =:= ?invalid -> find_longopt(Prefix, LongOpts, IsSingleDash, Option);
-    _ -> ?ambiguous
+    _ ->
+      case is_unambiguous(Candidate, Option) of
+        true -> find_longopt(Prefix, LongOpts, IsSingleDash, Option);
+        false -> ?ambiguous
+      end
   end;
 find_longopt(_Prefix, _LongOpts, _IsSingleDash, _Candidate) -> erlang:error(badarg).
 
+is_unambiguous(?invalid, _Option) -> true;
+is_unambiguous({_Name1, HasArg, Val}, {_Name2, HasArg, Val}) -> true;
+is_unambiguous(_, _) -> false.
+
 longopt_prefix([$- | Name], Prefix, _IsSingleDash) -> string:prefix(Name, Prefix);
 longopt_prefix(_Name, _Prefix, _IsSingleDash = true) -> nomatch;
 longopt_prefix(Name, Prefix, _IsSingleDash) -> string:prefix(Name, Prefix).