parse.y: relax `&' warning

* parse.y (parser_yylex): disable "`&' interpreted as argument
  prefix" warning when just followed by a symbol literal.
  [ruby-core:79926] [Misc #13283]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57955 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 6 insertions, 1 deletions

diff --git a/parse.y b/parse.y
index 0da381d758..01f0c9a64c 100644
--- a/parse.y
+++ b/parse.y
@@ -8147,7 +8147,12 @@ parser_yylex(struct parser_params *parser)
 	}
 	pushback(c);
 	if (IS_SPCARG(c)) {
-	    rb_warning0("`&' interpreted as argument prefix");
+	    if ((c != ':') ||
+		(c = peekc_n(1)) == -1 ||
+		!(c == '\'' || c == '"' ||
+		  is_identchar((lex_p+1), lex_pend, current_enc))) {
+		rb_warning0("`&' interpreted as argument prefix");
+	    }
 	    c = tAMPER;
 	}
 	else if (IS_BEG()) {