bail fast on file extensions we recognize as binary

lib/linguist/blob_helper.rb

@@ -90,6 +90,15 @@ module Linguist
       @detect_encoding ||= CharlockHolmes::EncodingDetector.new.detect(data) if data
     end
 
+    # Public: Is the blob binary according to its mime type
+    #
+    # Return true or false
+    def binary_mime_type?
+      if mime_type = Mime.lookup_mime_type_for(pathname.extname)
+        mime_type.binary?
+      end
+    end
+
     # Public: Is the blob binary?
     #
     # Return true or false

lib/linguist/repository.rb

@@ -67,6 +67,9 @@ module Linguist
       return if @computed_stats
 
       @enum.each do |blob|
+        # Skip binary file extensions
+        next if blob.binary_mime_type?
+
         # Skip vendored or generated blobs
         next if blob.vendored? || blob.generated? || blob.language.nil?