Java: Add example of missing sink generation.

Author: michaelnebel

java/ql/test/utils/modelgenerator/dataflow/CaptureSinkModels.ext.yml

@@ -7,6 +7,13 @@ extensions:
       - [ "p", "Sinks", False, "sink", "(Object)", "", "Argument[0]", "test-sink", "manual" ]
       - [ "p", "Sinks", False, "sink2", "(Object)", "", "Argument[0]", "test-sink2", "manual" ]
       - [ "p", "Sinks", False, "manualSinkAlreadyDefined", "(Object)", "", "Argument[0]", "test-sink", "manual" ]
+      - [ "p", "Sinks", False, "saveAndGet", "(Object)", "", "Argument[0]", "test-sink", "df-generated"]
+
+  - addsTo:
+      pack: codeql/java-all
+      extensible: sourceModel
+    data:
+      - [ "p", "Sinks", False, "saveAndGet", "(Object)", "", "ReturnValue", "test-source", "manual"]
 
   - addsTo:
       pack: codeql/java-all

java/ql/test/utils/modelgenerator/dataflow/p/Sinks.java

@@ -25,6 +25,14 @@ public void sink2(Object o) {}
   // neutral=p;Sinks;nosink;(Object);summary;df-generated
   public void nosink(Object o) {}
 
+  // Sink and Source defined in the extensible file next to the sink test.
+  // MISSING SINK
+  // neutral=p;Sinks;saveAndGet;(Object);summary;df-generated
+  public Object saveAndGet(Object o) {
+    sink(o);
+    return null;
+  }
+
   // sink=p;Sinks;true;copyFileToDirectory;(Path,Path,CopyOption[]);;Argument[0];path-injection;df-generated
   // sink=p;Sinks;true;copyFileToDirectory;(Path,Path,CopyOption[]);;Argument[1];path-injection;df-generated
   // neutral=p;Sinks;copyFileToDirectory;(Path,Path,CopyOption[]);summary;df-generated