qt6: fix "file name too long" error in gn tool

Fixes #5456

repos/libports/ports/qt6-host.hash

@@ -1 +1 @@
-1a0072de9fae10738f0d32d367ffff063e6cdc7b
+802b7ca16c8e96911c1a190e99f949e07abbb047

repos/libports/ports/qt6-host.port

@@ -6,3 +6,6 @@ DOWNLOADS := qt6.archive
 URL(qt6) := https://download.qt.io/archive/qt/6.6/6.6.2/single/qt-everywhere-src-6.6.2.tar.xz
 SHA(qt6) := 3c1e42b3073ade1f7adbf06863c01e2c59521b7cc2349df2f74ecd7ebfcb922d
 DIR(qt6) := src/lib/qt6
+
+PATCHES   := src/qt6/host/patches/qtwebengine_qtbug59769.patch
+PATCH_OPT := -p1 -d src/lib/qt6

repos/libports/src/qt6/host/patches/qtwebengine_qtbug59769.patch

@@ -0,0 +1,24 @@
+qtwebengine_qtbug59769.patch
+
+https://bugreports.qt.io/browse/QTBUG-59769
+
+diff --git a/qtwebengine/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc b/qtwebengine/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc
+index 6e1d2abf1d..c1d879bd2c 100644
+--- a/qtwebengine/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc
++++ b/qtwebengine/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc
+@@ -124,7 +124,15 @@ std::string NinjaActionTargetWriter::WriteRuleDefinition() {
+     // each invocation of the rule gets a different response file. This isn't
+     // strictly necessary for regular one-shot actions, but it's easier to
+     // just always define unique_name.
++
++    // filename too long issue.
+     std::string rspfile = custom_rule_name;
++
++    std::hash<std::string> hash_fn;
++    size_t hash_id = hash_fn(rspfile);
++
++    rspfile = std::to_string(hash_id);
++
+     if (!target_->sources().empty())
+       rspfile += ".$unique_name";
+     rspfile += ".rsp";