From 6bfcb769a8ace136ab44a7ae2c343c819655867e Mon Sep 17 00:00:00 2001
From: Alan Agius <alan.agius4@gmail.com>
Date: Tue, 9 Jun 2020 13:02:37 +0200
Subject: [PATCH] fix(@angular-devkit/build-angular): disable CSS `calc`
 optimizations

Disable `calc` optimizations due to several issues.

Closes #16910 closes #16875 and closes #17890
---
 .../angular-cli-files/plugins/optimize-css-webpack-plugin.ts  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/optimize-css-webpack-plugin.ts b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/optimize-css-webpack-plugin.ts
index 2cb6182178b5..7296e5c552bb 100644
--- a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/optimize-css-webpack-plugin.ts
+++ b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/optimize-css-webpack-plugin.ts
@@ -78,8 +78,10 @@ export class OptimizeCssWebpackPlugin {
 
           const cssNanoOptions: cssNano.CssNanoOptions = {
             preset: ['default', {
-              // Disable SVG optimization, as this can cause optimizations which are not compatible in all browsers.
+              // Disable SVG optimizations, as this can cause optimizations which are not compatible in all browsers.
               svgo: false,
+              // Disable `calc` optimizations, due to several issues. #16910, #16875, #17890
+              calc: false,
             }],
           };