# HG changeset patch
# User Felix Wolfsteller <felix.wolfsteller@intevation.de>
# Date 1324044352 0
# Node ID 5b6ba54d488a4f6f362a571dcb40c33ef2fd92fa
# Parent  b47d0464f0dbfc11e001408c0eec8837242c5b09
Never return null from a function which is documented to do so.

artifacts/trunk@3443 c6561f87-3c4e-4783-a992-168aeb5c3f6f

diff -r b47d0464f0db -r 5b6ba54d488a ChangeLog
--- a/ChangeLog	Fri Dec 16 09:14:14 2011 +0000
+++ b/ChangeLog	Fri Dec 16 14:05:52 2011 +0000
@@ -1,3 +1,8 @@
+2011-12-16	Felix Wolfsteller	<felix.wolfsteller@intevation.de>
+
+	* artifact-database/src/main/java/de/intevation/artifactdatabase/AbstractCallContext.java:
+	  (getDataProvider): Never return null.
+
 2011-12-16  Ingo Weinzierl <ingo@intevation.de>
 
 	* artifact-database/src/main/java/de/intevation/artifactdatabase/state/Output.java,
diff -r b47d0464f0db -r 5b6ba54d488a artifact-database/src/main/java/de/intevation/artifactdatabase/AbstractCallContext.java
--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/AbstractCallContext.java	Fri Dec 16 09:14:14 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/AbstractCallContext.java	Fri Dec 16 14:05:52 2011 +0000
@@ -7,8 +7,11 @@
  */
 package de.intevation.artifactdatabase;
 
+import org.apache.log4j.Logger;
+
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.HashMap;
 
 import de.intevation.artifacts.ArtifactDatabase;
@@ -25,6 +28,8 @@
  */
 public abstract class AbstractCallContext implements CallContext {
 
+    Logger logger = Logger.getLogger(AbstractCallContext.class);
+
     /**
      * The ArtifactDatabase instance.
      */
@@ -115,11 +120,16 @@
      * @return list (empty list if none found, never null).
      */
     public List<DataProvider> getDataProvider(Object key) {
-        return dataProviders != null
-            ? dataProviders.get(key)
-            : java.util.Collections.<DataProvider>emptyList();
+        if (dataProviders != null) {
+            List<DataProvider> list = dataProviders.get(key);
+            return list != null
+                ? list
+                : java.util.Collections.<DataProvider>emptyList();
+        }
+        return java.util.Collections.<DataProvider>emptyList();
     }
 
+
     /**
      * Let a DataProvider register itself with given key.
      * Multiple DataProvider can register under the same key.