fix problem where "Could not use {} for decompilation" error messages

increase with every usage

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/editor/BaseDecompiler.java

@@ -16,4 +16,8 @@ public List<Exception> getExceptions() {
 		return exceptions;
 	}
 
+	@Override
+	public void clearExceptions() {
+		exceptions.clear();
+	}
 }

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/editor/BaseDecompilerSourceMapper.java

@@ -158,7 +158,7 @@ public char[] findSource(IType type, IBinaryType info) {
 
 		classLocation = ""; //$NON-NLS-1$
 
-		usedDecompiler = decompile(null, type, exceptions, root, className);
+		usedDecompiler = decompile(type, exceptions, root, className);
 
 		if (noDecompiledSourceCodeAvailable(usedDecompiler)) {
 			if (usedDecompiler == null) {
@@ -260,9 +260,12 @@ private boolean fromInput(IType type) {
 		return false;
 	}
 
-	private IDecompiler decompile(IDecompiler decompiler, IType type, Collection<Exception> exceptions,
-			IPackageFragmentRoot root, String className) {
-		IDecompiler result = decompiler;
+	private IDecompiler decompile(IType type, Collection<Exception> exceptions, IPackageFragmentRoot root,
+			String className) {
+
+		originalDecompiler.clearExceptions();
+
+		IDecompiler result = null;
 
 		String pkg = type.getPackageFragment().getElementName().replace('.', '/');
 
@@ -277,13 +280,11 @@ private IDecompiler decompile(IDecompiler decompiler, IType type, Collection<Exc
 				String archivePath = getArchivePath(root);
 				classLocation += archivePath;
 
-				if (result == null) {
-					try (InputStream in = new ByteArrayInputStream(type.getClassFile().getBytes())) {
-						result = ClassUtil.checkAvailableDecompiler(originalDecompiler, in);
-					} catch (JavaModelException e) {
-						Logger.error(e.toString());
-						result = originalDecompiler;
-					}
+				try (InputStream in = new ByteArrayInputStream(type.getClassFile().getBytes())) {
+					result = ClassUtil.checkAvailableDecompiler(originalDecompiler, in);
+				} catch (JavaModelException e) {
+					Logger.error(e.toString());
+					result = originalDecompiler;
 				}
 				result.decompileFromArchive(archivePath, pkg, className);
 			} else {
@@ -306,9 +307,7 @@ private IDecompiler decompile(IDecompiler decompiler, IType type, Collection<Exc
 								+ className;
 					}
 
-					if (result == null) {
-						result = ClassUtil.checkAvailableDecompiler(originalDecompiler, new File(classLocation));
-					}
+					result = ClassUtil.checkAvailableDecompiler(originalDecompiler, new File(classLocation));
 					result.decompile(rootLocation, pkg, className);
 				} catch (JavaModelException e) {
 					exceptions.add(e);
@@ -325,7 +324,7 @@ private IDecompiler decompile(IDecompiler decompiler, IType type, Collection<Exc
 	}
 
 	@Override
-	public String decompile(String decompilerType, File file) {
+	public String decompileFile(String decompilerType, File file) {
 		IPreferenceStore prefs = JavaDecompilerPlugin.getDefault().getPreferenceStore();
 
 		Boolean displayNumber = null;
@@ -379,7 +378,6 @@ public String decompile(String decompilerType, File file) {
 		} else {
 			source.append(code);
 		}
-
 		return source.toString();
 	}
 

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/editor/DecompilerSourceMapper.java

@@ -174,5 +174,5 @@ protected IJavaElement findElement(IJavaElement elt, int position) {
 		return elt;
 	}
 
-	public abstract String decompile(String decompilerType, File file);
+	public abstract String decompileFile(String decompilerType, File file);
 }

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/editor/IDecompiler.java

@@ -53,6 +53,8 @@ public interface IDecompiler {
 	 */
 	List<Exception> getExceptions();
 
+	void clearExceptions();
+
 	/**
 	 * @return decompilation log specific to physical decompiler
 	 */

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/editor/JavaDecompilerClassFileEditor.java

@@ -324,7 +324,7 @@ protected void doSetInput(IEditorInput input) throws CoreException {
 			FileStoreEditorInput storeInput = (FileStoreEditorInput) input;
 			IPreferenceStore prefs = JavaDecompilerPlugin.getDefault().getPreferenceStore();
 			String decompilerType = prefs.getString(JavaDecompilerConstants.DECOMPILER_TYPE);
-			String source = DecompileUtil.decompiler(storeInput, decompilerType);
+			String source = DecompileUtil.decompileInput(storeInput, decompilerType);
 
 			if (source != null) {
 				String packageName = DecompileUtil.getPackageName(source);

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/util/ClassUtil.java

@@ -41,6 +41,7 @@ public static IDecompiler checkAvailableDecompiler(IDecompiler decompiler, Input
 
 		boolean debug = isDebug();
 		IDecompiler defaultDecompiler = getDebugDecompiler(classLevel, debug);
+		defaultDecompiler.clearExceptions();
 
 		if (decompiler.supportLevel(classLevel)) {
 			if (debug) {
@@ -128,7 +129,9 @@ public static IDecompiler getDebugDecompiler(int level, boolean debug) {
 			if (!defaultDecompiler.isPresent()) {
 				return null;
 			}
-			return defaultDecompiler.get().getDecompiler();
+			IDecompiler decompiler = defaultDecompiler.get().getDecompiler();
+			decompiler.clearExceptions();
+			return decompiler;
 		}
 		return null;
 	}

org.sf.feeling.decompiler/src/org/sf/feeling/decompiler/util/DecompileUtil.java

@@ -47,11 +47,10 @@ public static String decompile(IClassFile cf, String type, boolean always, boole
 		return origSrc;
 	}
 
-	public static String decompiler(FileStoreEditorInput input, String decompilerType) {
+	public static String decompileInput(FileStoreEditorInput input, String decompilerType) {
 		DecompilerSourceMapper sourceMapper = SourceMapperFactory.getSourceMapper(decompilerType);
 		File file = new File(input.getURI());
-		return sourceMapper.decompile(decompilerType, file);
-
+		return sourceMapper.decompileFile(decompilerType, file);
 	}
 
 	public static String getPackageName(String source) {