CHANGELOG

+v 7.2.21
+  - Add checks if blob is a lfs pointer, values for size and oid.
+
 v 7.2.20
   - Switch back to GitHub Linguist and bump rugged and other gem versions
   - Add method on repository to create branch

Gemfile.lock

 PATH
   remote: .
   specs:
-    gitlab_git (7.2.20)
+    gitlab_git (7.2.21)
       activesupport (~> 4.0)
       charlock_holmes (~> 0.7.3)
       github-linguist (~> 4.7.0)
@@ -10,7 +10,7 @@ PATH
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (4.2.4)
+    activesupport (4.2.5)
       i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
@@ -35,7 +35,7 @@ GEM
     escape_utils (1.1.0)
     ffi (1.8.1)
     formatador (0.2.4)
-    github-linguist (4.7.0)
+    github-linguist (4.7.2)
       charlock_holmes (~> 0.7.3)
       escape_utils (~> 1.1.0)
       mime-types (>= 1.19)
@@ -58,7 +58,7 @@ GEM
     lumberjack (1.0.3)
     method_source (0.8.1)
     mime-types (1.25.1)
-    minitest (5.8.2)
+    minitest (5.8.3)
     multi_json (1.10.1)
     parser (2.2.0.2)
       ast (>= 1.1, < 3.0)
@@ -121,3 +121,6 @@ DEPENDENCIES
   rubocop
   simplecov
   webmock
+
+BUNDLED WITH
+   1.10.6

VERSION

-7.2.20
+7.2.21

lib/gitlab_git/blob.rb

@@ -220,6 +220,39 @@ module Gitlab
       def name
         encode! @name
       end
+
+      # Valid LFS object pointer is a text file consisting of
+      # version
+      # oid
+      # size
+      # see https://github.com/github/git-lfs/blob/v1.1.0/docs/spec.md#the-pointer
+      def lfs_pointer?
+        has_lfs_version_key? && lfs_oid.present? && lfs_size.present?
+      end
+
+      def lfs_oid
+        if has_lfs_version_key?
+          oid = data.match(/(?<=sha256:)([0-9a-f]{64})/)
+          return oid[1] if oid
+        end
+
+        nil
+      end
+
+      def lfs_size
+        if has_lfs_version_key?
+          size = data.match(/(?<=size )([0-9]+)/)
+          return size[1] if size
+        end
+
+        nil
+      end
+
+      private
+
+      def has_lfs_version_key?
+        !empty? && text? && data.start_with?("version https://git-lfs.github.com/spec")
+      end
     end
   end
 end

spec/blob_spec.rb

@@ -244,4 +244,84 @@ describe Gitlab::Git::Blob do
       end.should be_false
     end
   end
+
+  describe :lfs_pointers do
+    context 'file a valid lfs pointer' do
+      let(:blob) do
+        Gitlab::Git::Blob.find(
+          repository,
+          '33bcff41c232a11727ac6d660bd4b0c2ba86d63d',
+          'files/lfs/image.jpg'
+        )
+      end
+
+      it { blob.lfs_pointer?.should == true }
+      it { blob.lfs_oid.should == "4206f951d2691c78aac4c0ce9f2b23580b2c92cdcc4336e1028742c0274938e0" }
+      it { blob.lfs_size.should == "19548" }
+      it { blob.id.should == "f4d76af13003d1106be7ac8c5a2a3d37ddf32c2a" }
+      it { blob.name.should == "image.jpg" }
+      it { blob.path.should == "files/lfs/image.jpg" }
+      it { blob.size.should == 130 }
+      it { blob.mode.should == "100644" }
+    end
+
+    describe 'file an invalid lfs pointer' do
+      context 'with correct version header but incorrect size and oid' do
+        let(:blob) do
+          Gitlab::Git::Blob.find(
+            repository,
+            '33bcff41c232a11727ac6d660bd4b0c2ba86d63d',
+            'files/lfs/archive-invalid.tar'
+          )
+        end
+
+        it { blob.lfs_pointer?.should == false }
+        it { blob.lfs_oid.should == nil }
+        it { blob.lfs_size.should == nil }
+        it { blob.id.should == "f8a898db217a5a85ed8b3d25b34c1df1d1094c46" }
+        it { blob.name.should == "archive-invalid.tar" }
+        it { blob.path.should == "files/lfs/archive-invalid.tar" }
+        it { blob.size.should == 43 }
+        it { blob.mode.should == "100644" }
+      end
+
+      context 'with correct version header and size but incorrect size and oid' do
+        let(:blob) do
+          Gitlab::Git::Blob.find(
+            repository,
+            '33bcff41c232a11727ac6d660bd4b0c2ba86d63d',
+            'files/lfs/picture-invalid.png'
+          )
+        end
+
+        it { blob.lfs_pointer?.should == false }
+        it { blob.lfs_oid.should == nil }
+        it { blob.lfs_size.should == "1575078" }
+        it { blob.id.should == "5ae35296e1f95c1ef9feda1241477ed29a448572" }
+        it { blob.name.should == "picture-invalid.png" }
+        it { blob.path.should == "files/lfs/picture-invalid.png" }
+        it { blob.size.should == 57 }
+        it { blob.mode.should == "100644" }
+      end
+
+      context 'with correct version header and size but invalid size and oid' do
+        let(:blob) do
+          Gitlab::Git::Blob.find(
+            repository,
+            '33bcff41c232a11727ac6d660bd4b0c2ba86d63d',
+            'files/lfs/file-invalid.zip'
+          )
+        end
+
+        it { blob.lfs_pointer?.should == false }
+        it { blob.lfs_oid.should == nil }
+        it { blob.lfs_size.should == nil }
+        it { blob.id.should == "d831981bd876732b85a1bcc6cc01210c9f36248f" }
+        it { blob.name.should == "file-invalid.zip" }
+        it { blob.path.should == "files/lfs/file-invalid.zip" }
+        it { blob.size.should == 60 }
+        it { blob.mode.should == "100644" }
+      end
+    end
+  end
 end