qt55: set Qt Quick import paths from NIX_PROFILES

pkgs/development/libraries/qt-5/5.5/default.nix

···
       qtmultimedia = callPackage ./qtmultimedia.nix {
         inherit (pkgs.gst_all_1) gstreamer gst-plugins-base;
       };
-      qtquick1 = callPackage ./qtquick1.nix {};
+      qtquick1 = callPackage ./qtquick1 {};
       qtquickcontrols = callPackage ./qtquickcontrols.nix {};
       qtscript = callPackage ./qtscript {};
       qtsensors = callPackage ./qtsensors.nix {};

pkgs/development/libraries/qt-5/5.5/qtquick1.nix pkgs/development/libraries/qt-5/5.5/qtquick1/default.nix

···
 
 qtSubmodule {
   name = "qtquick1";
+  patches = [ ./0001-nix-profiles-import-paths.patch ];
   qtInputs = [ qtscript qtsvg qtwebkit qtxmlpatterns ];
 }

pkgs/development/libraries/qt-5/5.5/qtquick1/0001-nix-profiles-import-paths.patch

···
+From bbc706b3fcb90ca3b2b51d5e3434145572152711 Mon Sep 17 00:00:00 2001
+From: Thomas Tuegel <[e-mail]>
+Date: Sat, 17 Oct 2015 09:29:51 -0500
+Subject: [PATCH] nix profiles import paths
+
+---
+ src/declarative/qml/qdeclarativeimport.cpp | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+diff --git a/src/declarative/qml/qdeclarativeimport.cpp b/src/declarative/qml/qdeclarativeimport.cpp
+index 9404834..d185ed5 100644
+--- a/src/declarative/qml/qdeclarativeimport.cpp
++++ b/src/declarative/qml/qdeclarativeimport.cpp
+@@ -725,6 +725,20 @@ QDeclarativeImportDatabase::QDeclarativeImportDatabase(QDeclarativeEngine *e)
+ 
+     addImportPath(installImportsPath);
+ 
++    // Add import paths derived from NIX_PROFILES.
++    const QByteArray nixProfilesEnv = qgetenv("NIX_PROFILES");
++    if (!nixProfilesEnv.isEmpty()) {
++        QLatin1Char pathSep(' ');
++        QStringList paths = QFile::decodeName(nixProfilesEnv).split(pathSep, QString::SkipEmptyParts);
++        for (QStringList::iterator it = paths.begin(); it != paths.end(); ++it) {
++            it->append("/lib/qt5/imports");
++            QString canonicalPath = QDir(*it).canonicalPath();
++            if (!canonicalPath.isEmpty()) {
++                addImportPath(canonicalPath);
++            }
++        }
++    }
++
+     // env import paths
+     QByteArray envImportPath = qgetenv("QML_IMPORT_PATH");
+     if (!envImportPath.isEmpty()) {
+-- 
+2.5.2
+