Fix https://github.com/plantuml/plantuml/issues/857

src/net/sourceforge/plantuml/DirWatcher.java

@@ -65,21 +65,23 @@ public class DirWatcher {
 	public List<GeneratedImage> buildCreatedFiles() throws IOException, InterruptedException {
 		boolean error = false;
 		final List<GeneratedImage> result = new ArrayList<>();
+		if (dir.listFiles() != null)
 			for (File f : dir.listFiles()) {
-			if (error) {
+				if (error)
 					continue;
-			}
+
-			if (f.isFile() == false) {
+				if (f.isFile() == false)
 					continue;
-			}
+
-			if (fileToProcess(f.getName()) == false) {
+				if (fileToProcess(f.getName()) == false)
 					continue;
-			}
+
 				final FileWatcher watcher = modifieds.get(f);
 
 				if (watcher == null || watcher.hasChanged()) {
 					final SourceFileReader sourceFileReader = new SourceFileReader(Defines.createWithFileName(f), f,
-						option.getOutputDir(), option.getConfig(), option.getCharset(), option.getFileFormatOption());
+							option.getOutputDir(), option.getConfig(), option.getCharset(),
+							option.getFileFormatOption());
 					final Set<File> files = FileWithSuffix.convert(sourceFileReader.getIncludedFiles());
 					files.add(f);
 					for (GeneratedImage g : sourceFileReader.getGeneratedImages()) {
@@ -96,21 +98,23 @@ public class DirWatcher {
 	}
 
 	public File getErrorFile() throws IOException, InterruptedException {
+		if (dir.listFiles() != null)
 			for (File f : dir.listFiles()) {
-			if (f.isFile() == false) {
+				if (f.isFile() == false)
 					continue;
-			}
+
-			if (fileToProcess(f.getName()) == false) {
+				if (fileToProcess(f.getName()) == false)
 					continue;
-			}
+
 				final FileWatcher watcher = modifieds.get(f);
 
 				if (watcher == null || watcher.hasChanged()) {
 					final SourceFileReader sourceFileReader = new SourceFileReader(Defines.createWithFileName(f), f,
-						option.getOutputDir(), option.getConfig(), option.getCharset(), option.getFileFormatOption());
+							option.getOutputDir(), option.getConfig(), option.getCharset(),
-				if (sourceFileReader.hasError()) {
+							option.getFileFormatOption());
+					if (sourceFileReader.hasError())
 						return f;
-				}
+
 				}
 			}
 		return null;

src/net/sourceforge/plantuml/DirWatcher2.java

@@ -71,14 +71,14 @@ public class DirWatcher2 {
 
 	public Map<File, Future<List<GeneratedImage>>> buildCreatedFiles() throws IOException, InterruptedException {
 		final Map<File, Future<List<GeneratedImage>>> result = new TreeMap<File, Future<List<GeneratedImage>>>();
-		if (dir.listFiles() != null) {
+		if (dir.listFiles() != null)
 			for (final File f : dir.listFiles()) {
-				if (f.isFile() == false) {
+				if (f.isFile() == false)
 					continue;
-				}
+
-				if (fileToProcess(f.getName()) == false) {
+				if (fileToProcess(f.getName()) == false)
 					continue;
-				}
+
 				final FileWatcher watcher = modifieds.get(f);
 
 				if (watcher == null || watcher.hasChanged()) {
@@ -106,7 +106,6 @@ public class DirWatcher2 {
 					result.put(f, value);
 				}
 			}
-		}
 		return Collections.unmodifiableMap(result);
 	}
 

src/net/sourceforge/plantuml/FileGroup.java

@@ -57,13 +57,13 @@ public class FileGroup {
 		this.pattern = pattern;
 		this.excluded = excluded;
 		this.option = option;
-		if (pattern.indexOf("*") == -1 && pattern.indexOf("?") == -1) {
+		if (pattern.indexOf("*") == -1 && pattern.indexOf("?") == -1)
 			initNoStar();
-		} else if (pattern.indexOf("**") != -1) {
+		else if (pattern.indexOf("**") != -1)
 			recurse();
-		} else {
+		else
 			initWithSimpleStar();
-		}
+
 		Collections.sort(result);
 
 	}
@@ -71,54 +71,53 @@ public class FileGroup {
 	private void recurse() {
 		final Matcher2 m = predirPath.matcher(pattern);
 		final boolean ok = m.find();
-		if (ok == false) {
+		if (ok == false)
 			throw new IllegalArgumentException();
-		}
+
 		final File parent;
-		if (m.group(1) == null) {
+		if (m.group(1) == null)
 			parent = new File(".");
-		} else {
+		else
 			parent = new File(m.group(1));
-		}
+
 		initWithDoubleStar(parent);
 	}
 
 	private void initNoStar() {
 		final File f = new File(pattern);
-		if (f.isDirectory()) {
+		if (f.isDirectory())
 			addSimpleDirectory(f);
-		} else if (f.isFile()) {
+		else if (f.isFile())
 			addResultFile(f);
-		}
+
 	}
 
 	private void addResultFile(final File f) {
 		final String path = getNormalizedPath(f);
-		for (String x : excluded) {
+		for (String x : excluded)
-			if (path.matches(toRegexp(x))) {
+			if (path.matches(toRegexp(x)))
 				return;
-			}
+
-		}
 		result.add(f);
 	}
 
 	private void addSimpleDirectory(File dir) {
-		if (OptionFlags.getInstance().isWord()) {
+		if (OptionFlags.getInstance().isWord())
 			addSimpleDirectory(dir, "(?i)^.*_extr\\d+\\.txt$");
-		} else {
+		else
 			addSimpleDirectory(dir, option.getPattern());
-		}
+
 	}
 
 	private void addSimpleDirectory(File dir, String pattern) {
-		if (dir.isDirectory() == false) {
+		if (dir.isDirectory() == false)
 			throw new IllegalArgumentException("dir=" + dir);
-		}
+
-		for (File f : dir.listFiles()) {
+		if (dir.listFiles() != null)
-			if (f.getName().matches(pattern)) {
+			for (File f : dir.listFiles())
+				if (f.getName().matches(pattern))
 					addResultFile(f);
-			}
+
-		}
 	}
 
 	private static String getNormalizedPath(File f) {
@@ -146,16 +145,15 @@ public class FileGroup {
 	}
 
 	private void initWithDoubleStar(File currentDir) {
+		if (currentDir.listFiles() != null)
 			for (File f : currentDir.listFiles()) {
 				if (f.isDirectory()) {
 					initWithDoubleStar(f);
 				} else if (f.isFile()) {
 					final String path = getNormalizedPath(f);
-				if (path.matches(toRegexp(pattern))) {
+					if (path.matches(toRegexp(pattern)))
 						addResultFile(f);
 				}
-
-			}
 			}
 
 	}

src/net/sourceforge/plantuml/activitydiagram3/ActivityDiagramFactory3.java

@@ -45,6 +45,7 @@ import net.sourceforge.plantuml.activitydiagram3.command.CommandActivityLong3;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandArrow3;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandArrowLong3;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandBackward3;
+import net.sourceforge.plantuml.activitydiagram3.command.CommandBackwardLong3;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandBreak;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandCase;
 import net.sourceforge.plantuml.activitydiagram3.command.CommandCircleSpot3;
@@ -125,6 +126,7 @@ public class ActivityDiagramFactory3 extends PSystemCommandFactory {
 		cmds.add(new CommandRepeatWhile3());
 		cmds.add(new CommandRepeatWhile3Multilines());
 		cmds.add(new CommandBackward3());
+		cmds.add(new CommandBackwardLong3());
 		cmds.add(new CommandWhile3());
 		cmds.add(new CommandWhileEnd3());
 		

src/net/sourceforge/plantuml/activitydiagram3/command/CommandActivityLong3.java

@@ -79,9 +79,7 @@ public class CommandActivityLong3 extends CommandMultilines2<ActivityDiagram3> {
 		final RegexResult line0 = getStartingPattern().matcher(lines.getFirst().getTrimmed().getString());
 		final Colors colors = color().getColor(diagram.getSkinParam().getThemeStyle(), line0,
 				diagram.getSkinParam().getIHtmlColorSet());
-		// final HtmlColor color =
+
-		// diagram.getSkinParam().getIHtmlColorSet().getColorIfValid(line0.get("COLOR",
-		// 0));
 		final BoxStyle style = BoxStyle.fromChar(lines.getLastChar());
 		lines = lines.removeStartingAndEnding(line0.get("DATA", 0), 1);
 		return diagram.addActivity(lines.toDisplay(), style, null, colors, null);

src/net/sourceforge/plantuml/activitydiagram3/command/CommandBackwardLong3.java

@@ -0,0 +1,98 @@
+/* ========================================================================
+ * PlantUML : a free UML diagram generator
+ * ========================================================================
+ *
+ * (C) Copyright 2009-2020, Arnaud Roques
+ *
+ * Project Info:  http://plantuml.com
+ * 
+ * If you like this project or if you find it useful, you can support us at:
+ * 
+ * http://plantuml.com/patreon (only 1$ per month!)
+ * http://plantuml.com/paypal
+ * 
+ * This file is part of PlantUML.
+ *
+ * PlantUML is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * PlantUML distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ *
+ * Original Author:  Arnaud Roques
+ *
+ *
+ */
+package net.sourceforge.plantuml.activitydiagram3.command;
+
+import net.sourceforge.plantuml.activitydiagram3.ActivityDiagram3;
+import net.sourceforge.plantuml.activitydiagram3.LinkRendering;
+import net.sourceforge.plantuml.activitydiagram3.ftile.BoxStyle;
+import net.sourceforge.plantuml.command.BlocLines;
+import net.sourceforge.plantuml.command.CommandExecutionResult;
+import net.sourceforge.plantuml.command.CommandMultilines2;
+import net.sourceforge.plantuml.command.MultilinesStrategy;
+import net.sourceforge.plantuml.command.regex.IRegex;
+import net.sourceforge.plantuml.command.regex.RegexConcat;
+import net.sourceforge.plantuml.command.regex.RegexLeaf;
+import net.sourceforge.plantuml.command.regex.RegexResult;
+import net.sourceforge.plantuml.graphic.color.ColorParser;
+import net.sourceforge.plantuml.graphic.color.ColorType;
+import net.sourceforge.plantuml.ugraphic.color.NoSuchColorException;
+
+public class CommandBackwardLong3 extends CommandMultilines2<ActivityDiagram3> {
+
+	public CommandBackwardLong3() {
+		super(getRegexConcat(), MultilinesStrategy.REMOVE_STARTING_QUOTE);
+	}
+
+	@Override
+	public String getPatternEnd() {
+		return "^(.*)" + CommandActivity3.endingGroup() + "$";
+	}
+
+	private static ColorParser color() {
+		return ColorParser.simpleColor(ColorType.BACK);
+	}
+
+	static IRegex getRegexConcat() {
+		return RegexConcat.build(CommandBackwardLong3.class.getName(), RegexLeaf.start(), //
+				RegexLeaf.spaceZeroOrMore(), //
+				new RegexLeaf("backward"), //
+				RegexLeaf.spaceZeroOrMore(), //
+				new RegexLeaf(":"), //
+				RegexLeaf.spaceZeroOrMore(), //
+				new RegexLeaf("DATA", "(.*)"), //
+				RegexLeaf.end());
+	}
+
+	@Override
+	protected CommandExecutionResult executeNow(ActivityDiagram3 diagram, BlocLines lines) throws NoSuchColorException {
+		lines = lines.removeEmptyColumns();
+		final RegexResult line0 = getStartingPattern().matcher(lines.getFirst().getTrimmed().getString());
+//		final Colors colors = color().getColor(diagram.getSkinParam().getThemeStyle(), line0,
+//				diagram.getSkinParam().getIHtmlColorSet());
+//
+		final BoxStyle style = BoxStyle.fromChar(lines.getLastChar());
+		lines = lines.removeStartingAndEnding(line0.get("DATA", 0), 1);
+		
+		final LinkRendering in = LinkRendering.none();
+		final LinkRendering out = LinkRendering.none();
+
+//		return diagram.addActivity(lines.toDisplay(), style, null, colors, null);
+		
+		return diagram.backward(lines.toDisplay(), style, in, out);
+
+//		return CommandExecutionResult.ok();
+	}
+}

src/net/sourceforge/plantuml/ant/PlantUmlTask.java

@@ -244,17 +244,18 @@ public class PlantUmlTask extends Task {
 			this.log(s);
 			throw new BuildException(s);
 		}
+		if (dir.listFiles() != null)
 			for (File f : dir.listFiles()) {
-			if (f.isFile() == false) {
+				if (f.isFile() == false)
 					continue;
-			}
+
-			if (fileToProcess(f.getName()) == false) {
+				if (fileToProcess(f.getName()) == false)
 					continue;
-			}
+
 				final boolean error = processingSingleFile(f);
-			if (error) {
+				if (error)
 					return f;
-			}
+
 			}
 		return null;
 	}

src/net/sourceforge/plantuml/security/SFile.java

@@ -172,6 +172,9 @@ public class SFile implements Comparable<SFile> {
 
 	public Collection<SFile> listFiles() {
 		final File[] tmp = internal.listFiles();
+		if (tmp == null)
+			return Collections.emptyList();
+		
 		final List<SFile> result = new ArrayList<>(tmp.length);
 		for (File f : tmp) {
 			result.add(new SFile(f));

src/net/sourceforge/plantuml/version/Version.java

@@ -80,7 +80,7 @@ public class Version {
 	}
 
 	public static int beta() {
-		final int beta = 0;
+		final int beta = 1;
 		return beta;
 	}