From 7ec2ffda93d297477a624cf2fbee3df068e79530 Mon Sep 17 00:00:00 2001
From: EricFromCanada <enk3@outlook.com>
Date: Tue, 18 Feb 2020 18:12:00 -0500
Subject: [PATCH] bump-formula-pr: warn when removing mirrors

---
 Library/Homebrew/dev-cmd/bump-formula-pr.rb | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Library/Homebrew/dev-cmd/bump-formula-pr.rb b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
index ba6b4c7bc1..2ba246a8cc 100644
--- a/Library/Homebrew/dev-cmd/bump-formula-pr.rb
+++ b/Library/Homebrew/dev-cmd/bump-formula-pr.rb
@@ -312,6 +312,17 @@ module Homebrew
 
     new_formula_version = formula_version(formula, requested_spec, new_contents)
 
+    if !new_mirror && !formula_spec.mirrors.empty?
+      if Homebrew.args.force?
+        opoo "#{formula}: Removing all mirrors because a --mirror= argument was not specified."
+      else
+        odie <<~EOS
+          #{formula}: a --mirror= argument for updating the mirror URL was not specified.
+          Use --force to remove all mirrors.
+        EOS
+      end
+    end
+
     if new_formula_version < old_formula_version
       formula.path.atomic_write(backup_file) unless args.dry_run?
       odie <<~EOS