Fix segfaults during generating of documentation.

This caused issued during build of rubygem-{webmock,ffi} and was fixed
as part of https://bugs.ruby-lang.org/issues/14261.

ruby-2.5.0-parse.y-assignable_error.patch

@@ -0,0 +1,80 @@
+From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+Date: Sun, 31 Dec 2017 11:25:38 +0000
+Subject: [PATCH] parse.y: assignable_error
+
+* parse.y (assignable_gen): should return valid NODE always even
+  on errors.  [ruby-core:84565] [Bug #14261]
+
+git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61523 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
+---
+ parse.c                 | 14 ++++----------
+ test/ruby/test_parse.rb |  6 ++++++
+ 2 files changed, 10 insertions(+), 10 deletions(-)
+
+diff --git a/parse.c b/parse.c
+index 08c3461f7096..c260a046dc33 100644
+--- a/parse.c
++++ b/parse.c
+@@ -6593,10 +6593,6 @@
+ #line 1984 "parse.y" /* yacc.c:1646  */
+     {
+ 			(yyval.node) = assignable(var_field((yyvsp[0].id)), 0, &(yyloc));
+-		    /*%%%*/
+-			if (!(yyval.node)) (yyval.node) = new_begin(0, &(yyloc));
+-		    /*%
+-		    %*/
+ 		    }
+ #line 6598 "parse.c" /* yacc.c:1646  */
+     break;
+@@ -6605,10 +6601,6 @@
+ #line 1992 "parse.y" /* yacc.c:1646  */
+     {
+ 			(yyval.node) = assignable(var_field((yyvsp[0].id)), 0, &(yyloc));
+-		    /*%%%*/
+-			if (!(yyval.node)) (yyval.node) = new_begin(0, &(yyloc));
+-		    /*%
+-		    %*/
+ 		    }
+ #line 6610 "parse.c" /* yacc.c:1646  */
+     break;
+@@ -16034,11 +16026,13 @@
+ #ifdef RIPPER
+     ID id = get_id(lhs);
+ # define assignable_result(x) (lhs)
++# define assignable_error() (lhs)
+ # define parser_yyerror(parser, x) (lhs = assign_error_gen(parser, lhs))
+ #else
+ # define assignable_result(x) assignable_result0(x, location)
++# define assignable_error() new_begin(0, location)
+ #endif
+-    if (!id) return assignable_result(0);
++    if (!id) return assignable_error();
+     switch (id) {
+       case keyword_self:
+ 	yyerror0("Can't change the value of self");
+@@ -16101,7 +16095,7 @@
+ 	compile_error(PARSER_ARG "identifier %"PRIsVALUE" is not valid to set", rb_id2str(id));
+     }
+   error:
+-    return assignable_result(0);
++    return assignable_error();
+ #undef assignable_result
+ #undef parser_yyerror
+ }
+diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
+index e26bcdc07e19..15c6245bac2e 100644
+--- a/test/ruby/test_parse.rb
++++ b/test/ruby/test_parse.rb
+@@ -746,6 +746,12 @@ def foo
+         end
+       END
+     end
++    assert_raise(SyntaxError) do
++      eval "#{<<~"begin;"}\n#{<<~'end;'}", nil, __FILE__, __LINE__+1
++      begin;
++        x, true
++      end;
++    end
+   end
+ 
+   def test_block_dup

ruby.spec

@@ -21,7 +21,7 @@
 %endif
 
 
-%global release 86
+%global release 87
 %{!?release_string:%global release_string %{?development_release:0.}%{release}%{?development_release:.%{development_release}}%{?dist}}
 
 # The RubyGems library has to stay out of Ruby directory three, since the
@@ -134,6 +134,9 @@ Patch9: ruby-2.3.1-Rely-on-ldd-to-detect-glibc.patch
 # Add Gem.operating_system_defaults to allow packagers to override defaults.
 # https://github.com/rubygems/rubygems/pull/2116
 Patch10: ruby-2.5.0-Add-Gem.operating_system_defaults.patch
+# Fix segfault during generating documentation.
+# https://bugs.ruby-lang.org/issues/14343
+Patch11: ruby-2.5.0-parse.y-assignable_error.patch
 
 Requires: %{name}-libs%{?_isa} = %{version}-%{release}
 Suggests: rubypick
@@ -516,6 +519,7 @@ rm -rf ext/fiddle/libffi*
 %patch7 -p1
 %patch9 -p1
 %patch10 -p1
+%patch11 -p1
 
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .
@@ -1058,6 +1062,9 @@ make check TESTS="-v $DISABLE_TESTS"
 %{gem_dir}/specifications/xmlrpc-%{xmlrpc_version}.gemspec
 
 %changelog
+* Tue Jan 09 2018 Vít Ondruch <vondruch@redhat.com> - 2.5.0-87
+- Fix segfaults during generating of documentation.
+
 * Tue Jan 02 2018 Vít Ondruch <vondruch@redhat.com> - 2.5.0-1
 - Upgrade to Ruby 2.5.0.