vscode: add hicolor icon (#473423)

pkgs/applications/editors/vscode/generic.nix

@@ -57,6 +57,7 @@
   ripgrep,
   hasVsceSign ? false,
   patchVSCodePath ? true,
+  imagemagick,
 }:
 
 stdenv.mkDerivation (
@@ -249,6 +250,7 @@ stdenv.mkDerivation (
 
     nativeBuildInputs = [
       unzip
+      imagemagick
     ]
     ++ lib.optionals stdenv.hostPlatform.isLinux [
       autoPatchelfHook
@@ -289,7 +291,13 @@ stdenv.mkDerivation (
           # These are named vscode.png, vscode-insiders.png, etc to match the name in upstream *.deb packages.
           + ''
             mkdir -p "$out/share/pixmaps"
-            cp "$out/lib/${libraryName}/resources/app/resources/linux/code.png" "$out/share/pixmaps/${iconName}.png"
+            icon_file="$out/lib/${libraryName}/resources/app/resources/linux/code.png"
+            cp "$icon_file" "$out/share/pixmaps/${iconName}.png"
+
+            # Dynamically determine size of icon and place in appropriate directory
+            size=$(identify -format "%wx%h" "$icon_file")
+            mkdir -p "$out/share/icons/hicolor/$size/apps"
+            cp "$icon_file" "$out/share/icons/hicolor/$size/apps/${iconName}.png"
           ''
         )
         # Override the previously determined VSCODE_PATH with the one we know to be correct