Handle conflicts where links point at symlinks

Fixes Homebrew/homebrew#30664.

1 files changed, 16 insertions, 0 deletions

diff --git a/Library/Homebrew/test/test_keg.rb b/Library/Homebrew/test/test_keg.rb
index e415be433..fa7d591dc 100644
--- a/Library/Homebrew/test/test_keg.rb
+++ b/Library/Homebrew/test/test_keg.rb
@@ -217,4 +217,20 @@ class LinkTests < Homebrew::TestCase
     assert_predicate link.resolved_path, :symlink?
     assert_predicate link.lstat, :symlink?
   end
+
+  def test_links_to_symlinks_are_not_removed
+    a = HOMEBREW_CELLAR.join("a", "1.0")
+    b = HOMEBREW_CELLAR.join("b", "1.0")
+
+    a.join("lib", "example").mkpath
+    a.join("lib", "example2").make_symlink "example"
+    b.join("lib", "example2").mkpath
+
+    Keg.new(a).link
+
+    lib = HOMEBREW_PREFIX.join("lib")
+    assert_equal 2, lib.children.length
+    assert_raises(Keg::ConflictError) { Keg.new(b).link }
+    assert_equal 2, lib.children.length
+  end
 end