From 75fa3b6baec324cfc6a3922aeb3013f02c4c6986 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Wed, 8 Jan 2020 17:33:36 +0100
Subject: [PATCH] unbreak missing argument error on long option

---
 src/builtin.cpp            | 11 ++++++++---
 src/builtin.h              |  2 +-
 src/builtin_argparse.cpp   |  4 ++--
 src/builtin_string.cpp     |  4 ++--
 tests/checks/argparse.fish |  3 +++
 5 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/builtin.cpp b/src/builtin.cpp
index 0a0057eb2..c41dc09d9 100644
--- a/src/builtin.cpp
+++ b/src/builtin.cpp
@@ -178,9 +178,14 @@ void builtin_unknown_option(parser_t &parser, io_streams_t &streams, const wchar
 
 /// Perform error reporting for encounter with missing argument.
 void builtin_missing_argument(parser_t &parser, io_streams_t &streams, const wchar_t *cmd,
-                              const wchar_t *opt) {
-    streams.err.append_format(BUILTIN_ERR_MISSING, cmd, opt + std::wcslen(opt) - 1);
-    builtin_print_error_trailer(parser, streams.err, cmd);
+                              const wchar_t *opt, bool print_hints) {
+    if (opt[0] == L'-' && opt[1] != L'-') {
+        opt += std::wcslen(opt) - 1;
+    }
+    streams.err.append_format(BUILTIN_ERR_MISSING, cmd, opt);
+    if (print_hints) {
+        builtin_print_error_trailer(parser, streams.err, cmd);
+    }
 }
 
 /// Print the backtrace and call for help that we use at the end of error messages.
diff --git a/src/builtin.h b/src/builtin.h
index d6774088c..2d37cbff1 100644
--- a/src/builtin.h
+++ b/src/builtin.h
@@ -96,7 +96,7 @@ void builtin_unknown_option(parser_t &parser, io_streams_t &streams, const wchar
                             const wchar_t *opt);
 
 void builtin_missing_argument(parser_t &parser, io_streams_t &streams, const wchar_t *cmd,
-                              const wchar_t *opt);
+                              const wchar_t *opt, bool print_hints = true);
 
 void builtin_print_error_trailer(parser_t &parser, output_stream_t &b, const wchar_t *cmd);
 
diff --git a/src/builtin_argparse.cpp b/src/builtin_argparse.cpp
index d93c0a090..3f3c1c43f 100644
--- a/src/builtin_argparse.cpp
+++ b/src/builtin_argparse.cpp
@@ -550,8 +550,8 @@ static int argparse_parse_flags(parser_t &parser, argparse_cmd_opts_t &opts,
     wgetopter_t w;
     while ((opt = w.wgetopt_long(argc, argv, short_options, long_options, &long_idx)) != -1) {
         if (opt == ':') {
-            const wchar_t *arg = argv[w.woptind - 1];
-            streams.err.append_format(BUILTIN_ERR_MISSING, cmd, arg + std::wcslen(arg) - 1);
+            builtin_missing_argument(parser, streams, cmd, argv[w.woptind - 1],
+                                     false /* print_hints */);
             return STATUS_INVALID_ARGS;
         } else if (opt == '?') {
             // It's not a recognized flag. See if it's an implicit int flag.
diff --git a/src/builtin_string.cpp b/src/builtin_string.cpp
index ca592e984..3bf7df9f2 100644
--- a/src/builtin_string.cpp
+++ b/src/builtin_string.cpp
@@ -458,8 +458,8 @@ static int parse_opts(options_t *opts, int *optind, int n_req_args, int argc, wc
             int retval = fn->second(argv, parser, streams, w, opts);
             if (retval != STATUS_CMD_OK) return retval;
         } else if (opt == ':') {
-            const wchar_t *arg = argv[w.woptind - 1];
-            string_error(streams, BUILTIN_ERR_MISSING, cmd, arg + std::wcslen(arg) - 1);
+            streams.err.append(L"string ");  // clone of string_error
+            builtin_missing_argument(parser, streams, cmd, argv[w.woptind - 1], false /* print_hints */);
             return STATUS_INVALID_ARGS;
         } else if (opt == '?') {
             string_unknown_option(parser, streams, cmd, argv[w.woptind - 1]);
diff --git a/tests/checks/argparse.fish b/tests/checks/argparse.fish
index e2f3f3a21..5c9ca8ec6 100644
--- a/tests/checks/argparse.fish
+++ b/tests/checks/argparse.fish
@@ -307,3 +307,6 @@ end
 # #6483 - error messages for missing arguments
 argparse -n foo q r/required= -- foo -qr
 # CHECKERR: foo: Expected argument for option r
+
+argparse r/required= -- foo --required
+# CHECKERR: argparse: Expected argument for option --required