Gracefully handle garbled URIs in Markdownsh-catch-invalid-uri-markdown

There are certain inputs that look like valid URIs that are accepted by URI
but not Addressable::URI. Handle the case where the latter fails.

Closes #41442

3 files changed, 11 insertions, 1 deletions

diff --git a/changelogs/unreleased/sh-catch-invalid-uri-markdown.yml b/changelogs/unreleased/sh-catch-invalid-uri-markdown.yml
new file mode 100644
index 00000000000..9b0233fe988
--- /dev/null
+++ b/changelogs/unreleased/sh-catch-invalid-uri-markdown.yml
@@ -0,0 +1,5 @@
+---
+title: Gracefully handle garbled URIs in Markdown
+merge_request:
+author:
+type: fixed
diff --git a/lib/banzai/filter/relative_link_filter.rb b/lib/banzai/filter/relative_link_filter.rb
index c1f933ec54b..5c197afd782 100644
--- a/lib/banzai/filter/relative_link_filter.rb
+++ b/lib/banzai/filter/relative_link_filter.rb
@@ -66,7 +66,7 @@ module Banzai
         if uri.relative? && uri.path.present?
           html_attr.value = rebuild_relative_uri(uri).to_s
         end
-      rescue URI::Error
+      rescue URI::Error, Addressable::URI::InvalidURIError
         # noop
       end
 
diff --git a/spec/lib/banzai/filter/relative_link_filter_spec.rb b/spec/lib/banzai/filter/relative_link_filter_spec.rb
index ef306f1cd4a..f38f0776303 100644
--- a/spec/lib/banzai/filter/relative_link_filter_spec.rb
+++ b/spec/lib/banzai/filter/relative_link_filter_spec.rb
@@ -76,6 +76,11 @@ describe Banzai::Filter::RelativeLinkFilter do
     expect { filter(act) }.not_to raise_error
   end
 
+  it 'does not raise an exception with a garbled path' do
+    act = link("open(/var/tmp/):%20/location%0Afrom:%20/test")
+    expect { filter(act) }.not_to raise_error
+  end
+
   it 'ignores ref if commit is passed' do
     doc = filter(link('non/existent.file'), commit: project.commit('empty-branch') )
     expect(doc.at_css('a')['href'])