Make unknown IFD fields accessible

remvee · Jun 23, 2022 · cdf2543 · cdf2543
1 parent eb8b8ab
commit cdf2543
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Showing 2 changed files with 15 additions and 10 deletions.
diff --git a/lib/exifr/tiff.rb b/lib/exifr/tiff.rb
@@ -482,10 +482,10 @@ def inspect # :nodoc:
     end
 
     class IFD # :nodoc:
-      attr_reader :type, :fields, :offset
+      attr_reader :type, :raw_fields, :fields, :offset
 
       def initialize(data, offset = nil, type = :image)
-        @data, @offset, @type, @fields = data, offset, type, {}
+        @data, @offset, @type, @raw_fields, @fields = data, offset, type, {}, {}
 
         pos = offset || @data.readlong(4)
         num = @data.readshort(pos)
@@ -546,15 +546,16 @@ def to_yaml_properties
 
     private
       def add_field(field)
-        return unless tag = TAG_MAPPING[@type][field.tag]
-        return if @fields[tag]
+        return if @raw_fields.include?(field.tag) # first encountered value wins
+        @raw_fields[field.tag] = field.value
 
-        if IFD_TAGS.include? tag
-          @fields[tag] = IFD.new(@data, field.offset, tag)
-        else
-          value = ADAPTERS[tag][field.value]
-          @fields[tag] = value.kind_of?(Array) && value.size == 1 ? value.first : value
-        end
+        return unless tag = TAG_MAPPING[@type][field.tag]
+        @fields[tag] = if IFD_TAGS.include?(tag)
+                         IFD.new(@data, field.offset, tag)
+                       else
+                         value = ADAPTERS[tag][field.value]
+                         value.kind_of?(Array) && value.size == 1 ? value.first : value
+                       end
       end
     end
 

diff --git a/tests/tiff_test.rb b/tests/tiff_test.rb
@@ -220,4 +220,8 @@ def test_methods_method
     assert t.methods(true).include?(:make)
     assert ! t.methods(false).include?(:make)
   end
+
+  def test_unknow_field
+    assert_equal [1, 1, 1, 1], TIFF.new(f('plain.tif')).first.raw_fields[0x0153] # TIFF Tag SampleFormat
+  end
 end