ScriptFinder: discover each script only once

Even if overlapping base script directories are added, such that a
script might be examined more than once, let's only add it to the first
time it is matched.

This will be useful to support Fiji 1.x's special handling of scripts in
the Plugins/Scripts subtree.

Author: ctrueden

src/main/java/org/scijava/script/ScriptFinder.java

@@ -32,7 +32,9 @@
 package org.scijava.script;
 
 import java.io.File;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import org.scijava.AbstractContextual;
 import org.scijava.MenuEntry;
@@ -78,6 +80,7 @@ public void findScripts(final List<ScriptInfo> scripts) {
 
 		int scriptCount = 0;
 
+		final HashSet<File> scriptFiles = new HashSet<File>();
 		for (final File directory : directories) {
 			if (!directory.exists()) {
 				log.warn("Ignoring non-existent scripts directory: " +
@@ -86,7 +89,8 @@ public void findScripts(final List<ScriptInfo> scripts) {
 			}
 			final MenuPath prefix = scriptService.getMenuPrefix(directory);
 			final MenuPath menuPath = prefix == null ? new MenuPath() : prefix;
-			scriptCount += discoverScripts(scripts, directory, menuPath);
+			scriptCount +=
+				discoverScripts(scripts, scriptFiles, directory, menuPath);
 		}
 
 		log.info("Found " + scriptCount + " scripts");
@@ -102,7 +106,7 @@ public void findScripts(final List<ScriptInfo> scripts) {
 	 * @param menuPath The menu path, which must not be {@code null}.
 	 */
 	private int discoverScripts(final List<ScriptInfo> scripts,
-		final File directory, final MenuPath menuPath)
+		final Set<File> scriptFiles, final File directory, final MenuPath menuPath)
 	{
 		final File[] fileList = directory.listFiles();
 		if (fileList == null) return 0; // directory does not exist
@@ -111,10 +115,12 @@ private int discoverScripts(final List<ScriptInfo> scripts,
 		final boolean isTopLevel = menuPath.size() == 0;
 
 		for (final File file : fileList) {
+			if (scriptFiles.contains(file)) continue; // script already added
+
 			final String name = file.getName().replace('_', ' ');
 			if (file.isDirectory()) {
 				// recurse into subdirectory
-				discoverScripts(scripts, file, subMenuPath(menuPath, name));
+				discoverScripts(scripts, scriptFiles, file, subMenuPath(menuPath, name));
 			}
 			else if (isTopLevel) {
 				// ignore scripts in toplevel script directories
@@ -125,6 +131,7 @@ else if (scriptService.canHandleFile(file)) {
 				final int dot = name.lastIndexOf('.');
 				final String noExt = dot <= 0 ? name : name.substring(0, dot);
 				scripts.add(createEntry(file, subMenuPath(menuPath, noExt)));
+				scriptFiles.add(file);
 				scriptCount++;
 			}
 		}