Merge branch 'master' into staging-next

There ver very many conflicts, basically all due to
name -> pname+version.  Fortunately, almost everything was auto-resolved
by kdiff3, and for now I just fixed up a couple evaluation problems,
as verified by the tarball job.  There might be some fallback to these
conflicts, but I believe it should be minimal.

Hydra nixpkgs: ?compare=1538299

pkgs/development/libraries/opencv/4.x.nix

@@ -1,5 +1,5 @@
 { lib, stdenv
-, fetchurl, fetchFromGitHub
+, fetchurl, fetchFromGitHub, fetchpatch
 , cmake, pkgconfig, unzip, zlib, pcre, hdf5
 , glog, boost, gflags, protobuf
 , config
@@ -160,6 +160,14 @@ stdenv.mkDerivation rec {
     cp --no-preserve=mode -r "${contribSrc}/modules" "$NIX_BUILD_TOP/source/opencv_contrib"
   '';
 
+  patches = [
+    (fetchpatch {
+      url = "https://github.com/opencv/opencv/commit/5691d998ead1d9b0542bcfced36c2dceb3a59023.patch";
+      name = "CVE-2019-14493.patch";
+      sha256 = "14qva9f5z10apz5q0skdyiclr9sgkhab4fzksy1w3b6j6hg4wm7m";
+    })
+  ];
+
   # This prevents cmake from using libraries in impure paths (which
   # causes build failure on non NixOS)
   # Also, work around https://github.com/NixOS/nixpkgs/issues/26304 with