fix poison mediawikiimporter output queue also after ExecutionException

in worker thread.
Writer of importer keeps needs a poison to close the file. On exception (e.g. OOM)
add a poison marker in outer most try/catch to assure output queue will terminate
in this condition too (and closes+renames the surrogate/in/xxx.prt file)

source/net/yacy/document/importer/MediawikiImporter.java

@@ -146,6 +146,11 @@ public class MediawikiImporter extends Thread implements Importer {
     @Override
     public void run() {
         this.start = System.currentTimeMillis();
+        final int threads = Math.max(2, Runtime.getRuntime().availableProcessors() - 1);
+        // out keeps a outputfile open until poisened, to make sure underlaying thread gets the end condition
+        // regardless of any exception (e.g. eof memory) a add(poison) is added to the most outer final block
+        final BlockingQueue<wikiparserrecord> out = new ArrayBlockingQueue<wikiparserrecord>(threads * 10);
+        final wikiparserrecord poison = newRecord();
         try {
             String targetstub = this.sourcefile.getName();
             int p = targetstub.lastIndexOf("\\.");
@@ -161,10 +166,7 @@ public class MediawikiImporter extends Thread implements Importer {
             StringBuilder sb = new StringBuilder();
             boolean page = false, text = false;
             String title = null;
-            final wikiparserrecord poison = newRecord();
-            final int threads = Math.max(2, Runtime.getRuntime().availableProcessors() - 1);
             final BlockingQueue<wikiparserrecord> in = new ArrayBlockingQueue<wikiparserrecord>(threads * 10);
-            final BlockingQueue<wikiparserrecord> out = new ArrayBlockingQueue<wikiparserrecord>(threads * 10);
             final ExecutorService service = Executors.newCachedThreadPool();
             final convertConsumer[] consumers = new convertConsumer[threads];
             final Future<?>[] consumerResults = (Future<?>[]) Array.newInstance(Future.class, threads);
@@ -261,8 +263,6 @@ public class MediawikiImporter extends Thread implements Importer {
                 for (int i = 0; i < threads; i++) {
                     consumerResults[i].get(10000, TimeUnit.MILLISECONDS);
                 }
-                out.put(poison);
-                writerResult.get(10000, TimeUnit.MILLISECONDS);
             } catch (final InterruptedException e) {
                 ConcurrentLog.logException(e);
             } catch (final ExecutionException e) {
@@ -271,11 +271,18 @@ public class MediawikiImporter extends Thread implements Importer {
                 ConcurrentLog.logException(e);
             } catch (final Exception e) {
                 ConcurrentLog.logException(e);
+            } finally {
+                out.put(poison); // output thread condition (for file.close)
+                writerResult.get(10000, TimeUnit.MILLISECONDS);
             }
         } catch (final IOException e) {
             ConcurrentLog.logException(e);
         } catch (final Exception e) {
             ConcurrentLog.logException(e);
+        } finally {
+            try {
+                out.put(poison); // out keeps output file open until poisened, to close file if exception happend in this block
+            } catch (InterruptedException ex) { }
         }
     }
 
@@ -733,10 +740,12 @@ public class MediawikiImporter extends Thread implements Importer {
                 ConcurrentLog.logException(e);
             } finally {
                 try {
-                    this.osw.write(SurrogateReader.SURROGATES_MAIN_ELEMENT_CLOSE + "\n");
-                    this.osw.close();
-                    final String finalfilename = this.targetstub + "." + this.fc + ".xml";
-                    new File(this.targetdir, this.outputfilename).renameTo(new File(this.targetdir, finalfilename));
+                    if (osw != null) { // maybe null on poison (immediately)
+                        this.osw.write(SurrogateReader.SURROGATES_MAIN_ELEMENT_CLOSE + "\n");
+                        this.osw.close();
+                        final String finalfilename = this.targetstub + "." + this.fc + ".xml";
+                        new File(this.targetdir, this.outputfilename).renameTo(new File(this.targetdir, finalfilename));
+                    }
                 } catch (final IOException e) {
                     ConcurrentLog.logException(e);
                 }