Fix parsing of default appearance strings to handle invalid PDFs with…

… symbolic DAs

CHANGELOG.md

@@ -19,6 +19,8 @@
 * [HexaPDF::Type::AcroForm::AppearanceGenerator] to work for files where check
   boxes don't define the name of the on state
 * [HexaPDF::Importer#import] to handle null values in all cases
+* [HexaPDF::Type::AcroForm::VariableTextField] to handle parsing of invalid PDFs
+  with symbolic appearance strings
 
 
 ## 0.46.0 - 2024-08-11

lib/hexapdf/type/acro_form/variable_text_field.rb

@@ -106,7 +106,7 @@ def self.parse_appearance_string(appearance_string, &block) # :yield: obj, param
               font_params[2] = HexaPDF::Content::ColorSpace.prenormalized_device_color(params)
             end
           end
-          HexaPDF::Content::Parser.parse(appearance_string.sub(/\/\//, '/'), &block)
+          HexaPDF::Content::Parser.parse(appearance_string.to_s.sub(/\/\//, '/'), &block)
           block_given? ? nil : font_params
         end
 

test/hexapdf/type/acro_form/test_variable_text_field.rb

@@ -108,6 +108,11 @@
                    @field.parse_default_appearance_string)
     end
 
+    it "converts the /DA to a string in case an invalid PDF uses a Symbol" do
+      @field[:DA] = :"1 g /F1 20 Tf"
+      assert_equal([:F1, 20, @color], @field.parse_default_appearance_string)
+    end
+
     it "fails if no /DA value is set and no default appearance string should be set" do
       @doc.acro_form.delete(:DA)
       @doc.config['acro_form.fallback_default_appearance'] = nil