Ignore weak ETAG prefix when comparing MATCH headers

Our metadata only contains the actual ETAG value, so we need
to use only that when comparing it.

lib/remote_storage/swift.rb

@@ -52,7 +52,7 @@ module RemoteStorage
 
       set_response_headers(res)
 
-      none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").split(",").map(&:strip)
+      none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").gsub(/^W\//, "").split(",").map(&:strip)
       server.halt 304 if none_match.include? %Q("#{res.headers[:etag]}")
 
       return res.body
@@ -71,7 +71,7 @@ module RemoteStorage
 
       server.headers["Content-Type"] = "application/ld+json"
 
-      none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").split(",").map(&:strip)
+      none_match = (server.env["HTTP_IF_NONE_MATCH"] || "").gsub(/^W\//, "").split(",").map(&:strip)
 
       if etag
         server.halt 304 if none_match.include? %Q("#{etag}")
@@ -139,7 +139,9 @@ module RemoteStorage
       url = url_for_key(user, directory, key)
 
       if required_match = server.env["HTTP_IF_MATCH"]
-        server.halt 412, "Precondition Failed" unless required_match == %Q("#{existing_metadata["e"]}")
+        unless required_match.gsub(/^W\//, "") == %Q("#{existing_metadata["e"]}")
+          server.halt 412, "Precondition Failed"
+        end
       end
       if server.env["HTTP_IF_NONE_MATCH"] == "*"
         server.halt 412, "Precondition Failed" unless existing_metadata.empty?
@@ -185,7 +187,9 @@ module RemoteStorage
       existing_metadata = redis.hgetall "rs:m:#{user}:#{directory}/#{key}"
 
       if required_match = server.env["HTTP_IF_MATCH"]
-        server.halt 412, "Precondition Failed" unless required_match == %Q("#{existing_metadata["e"]}")
+        unless required_match.gsub(/^W\//, "") == %Q("#{existing_metadata["e"]}")
+          server.halt 412, "Precondition Failed"
+        end
       end
 
       begin

spec/swift/app_spec.rb

@@ -249,6 +249,22 @@ describe "App" do
           last_response.headers["Etag"].must_equal "\"newetag\""
         end
 
+        it "allows the request if the header contains a weak ETAG matching the current ETag" do
+          header "If-Match", "W/\"oldetag\""
+
+          put_stub = OpenStruct.new(headers: {
+            etag: "newetag",
+            last_modified: "Fri, 04 Mar 2016 12:20:18 GMT"
+          })
+
+          RestClient.stub :put, put_stub do
+            put "/phil/food/aguacate", "aye"
+          end
+
+          last_response.status.must_equal 200
+          last_response.headers["Etag"].must_equal "\"newetag\""
+        end
+
         it "fails the request if the header does not match the current ETag" do
           header "If-Match", "someotheretag"
 
@@ -473,6 +489,16 @@ describe "App" do
           last_response.status.must_equal 200
         end
 
+        it "succeeds when the header contains a weak ETAG matching the current ETag" do
+          header "If-Match", "W/\"bla\""
+
+          RestClient.stub :delete, "" do
+            delete "/phil/food/aguacate"
+          end
+
+          last_response.status.must_equal 200
+        end
+
         it "fails the request if it does not match the current ETag" do
           header "If-Match", "someotheretag"
 
@@ -562,6 +588,40 @@ describe "App" do
           last_response.body.must_equal "Not Found"
         end
 
+        it "responds with 304 when IF_NONE_MATCH header contains the ETag" do
+          header "If-None-Match", "\"0815etag\""
+
+          get_stub = OpenStruct.new(body: "si", headers: {
+            etag: "0815etag",
+            last_modified: "Fri, 04 Mar 2016 12:20:18 GMT",
+            content_type: "text/plain; charset=utf-8",
+            content_length: 2
+          })
+
+          RestClient.stub :get, get_stub do
+            get "/phil/food/aguacate"
+          end
+
+          last_response.status.must_equal 304
+        end
+
+        it "responds with 304 when IF_NONE_MATCH header contains weak ETAG matching the current ETag" do
+          header "If-None-Match", "W/\"0815etag\""
+
+          get_stub = OpenStruct.new(body: "si", headers: {
+            etag: "0815etag",
+            last_modified: "Fri, 04 Mar 2016 12:20:18 GMT",
+            content_type: "text/plain; charset=utf-8",
+            content_length: 2
+          })
+
+          RestClient.stub :get, get_stub do
+            get "/phil/food/aguacate"
+          end
+
+          last_response.status.must_equal 304
+        end
+
       end
 
       describe "directory listings" do
@@ -587,6 +647,13 @@ describe "App" do
           last_response.status.must_equal 304
         end
 
+        it "responds with 304 when IF_NONE_MATCH header contains weak ETAG matching the ETag" do
+          header "If-None-Match", "W/\"f9f85fbf5aa1fa378fd79ac8aa0a457d\""
+          get "/phil/food/"
+
+          last_response.status.must_equal 304
+        end
+
         it "contains all items in the directory" do
           get "/phil/food/"