kinit: Increase environment size limit

start_kdeinit reads its environment over a pipe from start_kdeinit_wrapper. For
security, each environment entry must be smaller than 4kb by default. Qt-based
applications in Nixpkgs may have larger environments, and the recent upgrade to
Plasma 5.17 pushed start_kdeinit_wrapper over the limit. The limit is now
extended to 16kb.

This problem was not detected during testing because the failure is silent:
start_kdeinit will continue with an empty environment. In other circumstances,
this strategy might work, but it does not work on NixOS. This failure is now
treated as a fatal error.

Fixes: #79707

pkgs/development/libraries/kde-frameworks/kinit/default.nix

@@ -14,7 +14,12 @@ mkDerivation {
   buildInputs = [
     kconfig kcrash ki18n kio kservice kwindowsystem
   ];
-  patches = copyPathsToStore (lib.readPathsFromFile ./. ./series);
+  patches = [
+    ./0001-kinit-libpath.patch
+    ./0002-start_kdeinit-path.patch
+    ./0003-kdeinit-extra-libs.patch
+    ./0004-start_kdeinit-environ-hard-limit.patch
+  ];
   CXXFLAGS = [
     ''-DNIXPKGS_KF5_KIOCORE=\"${getLib kio}/lib/libKF5KIOCore.so.5\"''
     ''-DNIXPKGS_KF5_PARTS=\"${getLib kparts}/lib/libKF5Parts.so.5\"''