From 68cc02588d4659c77b9e5bfab7ff848c2b5248ca Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Sat, 29 Jul 2023 13:10:16 +0300
Subject: [PATCH] qt5: include qttranslations properly

Qt loads its own translations from a hardcoded path, and those are used
(among other things) for determining RTL layout preferences in applications,
so they are definitely something we want to have.

This adds a qtbase/qttools rebuild to the chain, but it's fast enough that it's
probably fine.

Another approach would be to load translation paths from the environment,
and inject it in wrapQtAppsHook, but that seems like more complexity
for very questionable build time savings.
---
 pkgs/development/libraries/qt-5/5.15/default.nix     | 12 +++++++++++-
 pkgs/development/libraries/qt-5/modules/qtbase.nix   |  3 +++
 pkgs/development/libraries/qt-5/modules/qttools.nix  |  2 +-
 .../libraries/qt-5/modules/qttranslations.nix        |  3 ++-
 pkgs/development/libraries/qt-5/qtModule.nix         |  2 +-
 5 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/libraries/qt-5/5.15/default.nix b/pkgs/development/libraries/qt-5/5.15/default.nix
index 5ae5102abeee..ac4614d2aee1 100644
--- a/pkgs/development/libraries/qt-5/5.15/default.nix
+++ b/pkgs/development/libraries/qt-5/5.15/default.nix
@@ -331,4 +331,14 @@ let
       } ../hooks/wrap-qt-apps-hook.sh;
     };
 
-in makeScopeWithSplicing (generateSplicesForMkScope "qt5") (_: {}) (_: {}) addPackages
+  baseScope = makeScopeWithSplicing (generateSplicesForMkScope "qt5") (_: {}) (_: {}) addPackages;
+
+  bootstrapScope = baseScope.overrideScope(final: prev: {
+    qtbase = prev.qtbase.override { qttranslations = null; };
+    qtdeclarative = null;
+  });
+
+  finalScope = baseScope.overrideScope(final: prev: {
+    qttranslations = bootstrapScope.qttranslations;
+  });
+in finalScope
diff --git a/pkgs/development/libraries/qt-5/modules/qtbase.nix b/pkgs/development/libraries/qt-5/modules/qtbase.nix
index de73bcbe2772..9f0feaf94e58 100644
--- a/pkgs/development/libraries/qt-5/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtbase.nix
@@ -15,6 +15,7 @@
   # optional dependencies
 , cups ? null, postgresql ? null
 , withGtk3 ? false, dconf, gtk3
+, qttranslations ? null
 
   # options
 , libGLSupported ? !stdenv.isDarwin
@@ -310,6 +311,8 @@ stdenv.mkDerivation (finalAttrs: {
     ] ++ lib.optionals (mysqlSupport) [
       "-L" "${libmysqlclient}/lib"
       "-I" "${libmysqlclient}/include"
+    ] ++ lib.optional (qttranslations != null) [
+      "-translationdir" "${qttranslations}/translations"
     ]
   );
 
diff --git a/pkgs/development/libraries/qt-5/modules/qttools.nix b/pkgs/development/libraries/qt-5/modules/qttools.nix
index be96236d7285..bac70d146bf9 100644
--- a/pkgs/development/libraries/qt-5/modules/qttools.nix
+++ b/pkgs/development/libraries/qt-5/modules/qttools.nix
@@ -36,7 +36,7 @@ qtModule {
     "bin/macdeployqt"
   ];
 
-  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin ''-DNIXPKGS_QMLIMPORTSCANNER="${qtdeclarative.dev}/bin/qmlimportscanner"'';
+  env.NIX_CFLAGS_COMPILE = lib.optionalString (stdenv.isDarwin && qtdeclarative != null) ''-DNIXPKGS_QMLIMPORTSCANNER="${qtdeclarative.dev}/bin/qmlimportscanner"'';
 
   setupHook = ../hooks/qttools-setup-hook.sh;
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qttranslations.nix b/pkgs/development/libraries/qt-5/modules/qttranslations.nix
index f49a4eb9a85d..bcd52cdc4a8f 100644
--- a/pkgs/development/libraries/qt-5/modules/qttranslations.nix
+++ b/pkgs/development/libraries/qt-5/modules/qttranslations.nix
@@ -2,5 +2,6 @@
 
 qtModule {
   pname = "qttranslations";
-  qtInputs = [ qttools ];
+  nativeBuildInputs = [ qttools ];
+  outputs = [ "out" ];
 }
diff --git a/pkgs/development/libraries/qt-5/qtModule.nix b/pkgs/development/libraries/qt-5/qtModule.nix
index 9abd9fabc957..bddbf254c5f7 100644
--- a/pkgs/development/libraries/qt-5/qtModule.nix
+++ b/pkgs/development/libraries/qt-5/qtModule.nix
@@ -17,7 +17,7 @@ mkDerivation (args // {
   patches = (args.patches or []) ++ (patches.${pname} or []);
 
   nativeBuildInputs = (args.nativeBuildInputs or []) ++ [ perl self.qmake ];
-  propagatedBuildInputs = args.qtInputs ++ (args.propagatedBuildInputs or []);
+  propagatedBuildInputs = (args.qtInputs or []) ++ (args.propagatedBuildInputs or []);
 
   outputs = args.outputs or [ "out" "dev" ];
   setOutputFlags = args.setOutputFlags or false;