gnu: QtWebKit: Fix building with Bison 3.7.

* gnu/packages/patches/qtwebkit-fix-building-with-bison-3.7.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/qt.scm (qtwebkit)[source]: Use it.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu/local.mk

@@ -1657,6 +1657,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/quassel-qt-514-compat.patch		\
   %D%/packages/patches/quickswitch-fix-dmenu-check.patch	\
   %D%/packages/patches/qtwebkit-pbutils-include.patch		\
+  %D%/packages/patches/qtwebkit-fix-building-with-bison-3.7.patch \
   %D%/packages/patches/qtwebkit-fix-building-with-python-3.9.patch	\
   %D%/packages/patches/qtwebkit-fix-building-with-icu-68.patch	\
   %D%/packages/patches/qtwebkit-fix-building-with-glib-2.68.patch	\

gnu/packages/patches/qtwebkit-fix-building-with-bison-3.7.patch

@@ -0,0 +1,54 @@
+Fix build with Bison 3.7
+
+https://bugs.gentoo.org/736499
+
+Patch copied from upstream source repository:
+
+https://github.com/qtwebkit/qtwebkit/commit/d92b11fea65364fefa700249bd3340e0cd4c5b31
+
+From d92b11fea65364fefa700249bd3340e0cd4c5b31 Mon Sep 17 00:00:00 2001
+From: Dmitry Shachnev <mitya57@gmail.com>
+Date: Tue, 4 Aug 2020 21:04:06 +0300
+Subject: [PATCH] Let Bison generate the header directly, to fix build with
+ Bison 3.7
+
+Starting with Bison 3.7, the generated C++ file #include's the header
+by default, instead of duplicating it. So we should not delete it.
+
+Remove the code to add #ifdef guards to the header, since Bison adds
+them itself since version 2.6.3.
+---
+ Source/WebCore/css/makegrammar.pl | 21 +--------------------
+ 1 file changed, 1 insertion(+), 20 deletions(-)
+
+diff --git a/Source/WebCore/css/makegrammar.pl b/Source/WebCore/css/makegrammar.pl
+index 5d63b08102eb5..9435701c70612 100644
+--- a/Source/WebCore/css/makegrammar.pl
++++ b/Source/WebCore/css/makegrammar.pl
+@@ -73,25 +73,6 @@
+ }
+ 
+ my $fileBase = File::Spec->join($outputDir, $filename);
+-my @bisonCommand = ($bison, "-d", "-p", $symbolsPrefix, $grammarFilePath, "-o", "$fileBase.cpp");
++my @bisonCommand = ($bison, "--defines=$fileBase.h", "-p", $symbolsPrefix, $grammarFilePath, "-o", "$fileBase.cpp");
+ push @bisonCommand, "--no-lines" if $^O eq "MSWin32"; # Work around bug in bison >= 3.0 on Windows where it puts backslashes into #line directives.
+ system(@bisonCommand) == 0 or die;
+-
+-open HEADER, ">$fileBase.h" or die;
+-print HEADER << "EOF";
+-#ifndef CSSGRAMMAR_H
+-#define CSSGRAMMAR_H
+-EOF
+-
+-open HPP, "<$fileBase.cpp.h" or open HPP, "<$fileBase.hpp" or die;
+-while (<HPP>) {
+-    print HEADER;
+-}
+-close HPP;
+-
+-print HEADER "#endif\n";
+-close HEADER;
+-
+-unlink("$fileBase.cpp.h");
+-unlink("$fileBase.hpp");
+-

gnu/packages/qt.scm

@@ -2625,6 +2625,7 @@ different kinds of sliders, and much more.")
          (base32
           "1rm9sjkabxna67dl7myx9d9vpdyfxfdhrk9w7b94srkkjbd2d8cw"))
         (patches (search-patches "qtwebkit-pbutils-include.patch"
+                                 "qtwebkit-fix-building-with-bison-3.7.patch"
                                  "qtwebkit-fix-building-with-glib-2.68.patch"
                                  "qtwebkit-fix-building-with-icu-68.patch"
                                  "qtwebkit-fix-building-with-python-3.9.patch"))))