kdePackages.koi: patch hardcoded binary paths

Co-authored-by: alexyao2015 <33379584+alexyao2015@users.noreply.github.com>

pkgs/kde/third-party/koi/0001-locate-plasma-tools.patch

@@ -0,0 +1,44 @@
+diff --git a/src/plugins/colorscheme.cpp b/src/plugins/colorscheme.cpp
+index 7c51806..4d8015b 100644
+--- a/src/plugins/colorscheme.cpp
++++ b/src/plugins/colorscheme.cpp
+@@ -3,16 +3,7 @@
+ #include <QProcess>
+ 
+ void ColorScheme::setTheme(QString themeName) {
+-  QProcess process;
+-  QString locateProgram = "whereis";
+-  QStringList programToLocate = {"plasma-apply-colorscheme"};
+-
+-  process.start(locateProgram, programToLocate);
+-  process.waitForFinished();
+-
+-  QString program(process.readAllStandardOutput());
+-  program.replace("plasma-apply-colorscheme: ", "");
+-  program.replace("\n", "");
++  QString program("@plasma-apply-colorscheme@");
+ 
+   QStringList arguments{themeName};
+   QProcess::startDetached(program, arguments);
+diff --git a/src/plugins/icons.cpp b/src/plugins/icons.cpp
+index 1cc306f..745d042 100644
+--- a/src/plugins/icons.cpp
++++ b/src/plugins/icons.cpp
+@@ -5,16 +5,7 @@
+ void Icons::setTheme(QString iconTheme) {
+ 
+   // locate plasma-changeicons program
+-  QProcess process;
+-  QString locateProgram = "whereis";
+-  QStringList programToLocate = {"plasma-changeicons"};
+-
+-  process.start(locateProgram, programToLocate);
+-  process.waitForFinished();
+-
+-  QString program(process.readAllStandardOutput());
+-  program.replace("plasma-changeicons: ", "");
+-  program.replace("\n", "");
++  QString program("@plasma-changeicons@");
+ 
+   // apply the icon theme
+   QStringList arguments{iconTheme};

pkgs/kde/third-party/koi/default.nix

@@ -7,6 +7,10 @@
   kcoreaddons,
   kwidgetsaddons,
   wrapQtAppsHook,
+  kdbusaddons,
+  kde-cli-tools,
+  plasma-workspace,
+  qtstyleplugin-kvantum,
 }:
 stdenv.mkDerivation (finalAttrs: {
   pname = "koi";
@@ -19,6 +23,27 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-fXLGlq41Qwdp0cYJcNqPlYnlpVXsZk0imYxP7Bgdcvw=";
   };
 
+  patches = [
+    # koi tries to access KDE utility binaries at their absolute paths or by using `whereis`.
+    # We patch the absolute paths below in `postPatch` and replace the `whereis` invocations
+    # here with a placeholder that is also substituted in `postPatch`.
+    ./0001-locate-plasma-tools.patch
+  ];
+
+  postPatch = ''
+    substituteInPlace src/utils.cpp \
+      --replace-fail /usr/bin/kquitapp6 ${lib.getExe' kdbusaddons "kquitapp6"} \
+      --replace-fail /usr/bin/kstart ${lib.getExe' kde-cli-tools "kstart"}
+    substituteInPlace src/plugins/plasmastyle.cpp \
+      --replace-fail /usr/bin/plasma-apply-desktoptheme ${lib.getExe' plasma-workspace "plasma-apply-desktoptheme"}
+    substituteInPlace src/plugins/colorscheme.cpp \
+      --replace-fail '@plasma-apply-colorscheme@' ${lib.getExe' plasma-workspace "plasma-apply-colorscheme"}
+    substituteInPlace src/plugins/icons.cpp \
+      --replace-fail '@plasma-changeicons@' ${plasma-workspace}/libexec/plasma-changeicons
+    substituteInPlace src/plugins/kvantumstyle.cpp \
+      --replace-fail /usr/bin/kvantummanager ${lib.getExe' qtstyleplugin-kvantum "kvantummanager"}
+  '';
+
   nativeBuildInputs = [
     cmake
     wrapQtAppsHook