resolves #3526 return nil if name passed to Asciidoctor::SafeMode.value_for_name is not recognized (PR #4496)

4 files changed, 13 insertions, 2 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 414322b4..82a9fbd2 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -62,6 +62,7 @@ Improvements::
   * Add single and double role hint to `<quote>` tag in DocBook output (#2947)
   * Use safe navigation to avoid crashing when querying for extensions
   * Remove empty line at top of table cells in manpage output (#4482) (*@strager*)
+  * Return `nil` if name passed to `Asciidoctor::SafeMode.value_for_name` is not recognized (#3526)
 
 Bug Fixes::
 
diff --git a/lib/asciidoctor.rb b/lib/asciidoctor.rb
index 45c28f6a..386b90c4 100644
--- a/lib/asciidoctor.rb
+++ b/lib/asciidoctor.rb
@@ -92,7 +92,7 @@ module Asciidoctor
     @names_by_value = (constants false).map {|sym| [(const_get sym), sym.to_s.downcase] }.sort {|(a), (b)| a <=> b }.to_h
 
     def self.value_for_name name
-      const_get name.upcase, false
+      const_get name.upcase, false rescue nil
     end
 
     def self.name_for_value value
diff --git a/lib/asciidoctor/document.rb b/lib/asciidoctor/document.rb
index af5fb51d..71fb887a 100644
--- a/lib/asciidoctor/document.rb
+++ b/lib/asciidoctor/document.rb
@@ -323,7 +323,7 @@ class Document < AbstractBlock
         # be permissive in case API user wants to define new levels
         @safe = safe_mode
       else
-        @safe = (SafeMode.value_for_name safe_mode) rescue SafeMode::SECURE
+        @safe = (SafeMode.value_for_name safe_mode) || SafeMode::SECURE
       end
       input_mtime = options.delete :input_mtime
       @compat_mode = attr_overrides.key? 'compat-mode'
diff --git a/test/api_test.rb b/test/api_test.rb
index 02e93c08..91839bbf 100644
--- a/test/api_test.rb
+++ b/test/api_test.rb
@@ -2078,4 +2078,14 @@ context 'API' do
       refute doc.blocks[1].sections?
     end
   end
+
+  context 'SafeMode' do
+    test 'should return nil if safe mode value not recognized' do
+      assert_nil Asciidoctor::SafeMode.name_for_value 99
+    end
+
+    test 'should return nil if safe mode name not recognized' do
+      assert_nil Asciidoctor::SafeMode.value_for_name 'unknown'
+    end
+  end
 end