Modify flow no longer produces elements for empty streams

slicebox · May 26, 2017 · d3677d7 · d3677d7
1 parent 160f7f4
commit d3677d7
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/src/main/scala/se/nimsa/dcm4che/streams/DicomFlows.scala b/src/main/scala/se/nimsa/dcm4che/streams/DicomFlows.scala
@@ -234,10 +234,12 @@ object DicomFlows {
           var sequenceDepth = 0
           var bigEndian = false
           var explicitVR = true
+          var hasAttributes = false
 
           def updateSyntax(header: DicomHeader): Unit = {
             bigEndian = header.bigEndian
             explicitVR = header.explicitVR
+            hasAttributes = true
           }
 
           def headerAndValue(tag: Int): List[DicomPart] = {
@@ -291,11 +293,13 @@ object DicomFlows {
           case s: DicomSequenceDelimitation =>
             sequenceDepth -= 1
             s :: Nil
-          case DicomEndMarker =>
+          case DicomEndMarker if hasAttributes =>
             modificationsLeft
               .filter(_.insert)
               .sortBy(_.tag)
               .flatMap(modification => headerAndValue(modification.tag))
+          case DicomEndMarker =>
+            Nil
           case part =>
             part :: Nil
         }

diff --git a/src/test/scala/se/nimsa/dcm4che/streams/DicomFlowsTest.scala b/src/test/scala/se/nimsa/dcm4che/streams/DicomFlowsTest.scala
@@ -334,8 +334,17 @@ class DicomFlowsTest extends TestKit(ActorSystem("DicomAttributesSinkSpec")) wit
       .expectHeader(Tag.PatientName, VR.PN, patientNameJohnDoe.length - 8)
       .expectValueChunk(patientNameJohnDoe.drop(8))
       .expectDicomComplete()
+  }
+
+  it should "not insert attributes if dataset contains no attributes" in {
+    val source = Source.empty
+      .via(new DicomPartFlow())
+      .via(modifyFlow(TagModification(Tag.SeriesDate, _ => studyDate.drop(8), insert = true)))
 
+    source.runWith(TestSink.probe[DicomPart])
+      .expectDicomComplete()
   }
+
   "The deflate flow" should "recreate the dicom parts of a dataset which has been deflated and inflated again" in {
     val bytes = fmiGroupLength(tsuidExplicitLE) ++ tsuidExplicitLE ++ patientNameJohnDoe ++ studyDate