core: fix issues reported by coverity

jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java

@@ -338,18 +338,23 @@ public class RegionMaker {
 			InstructionRemover.unbindInsn(mth, exitInsn);
 		}
 
-		block = getNextBlock(block);
+		BlockNode body = getNextBlock(block);
+		if (body == null) {
+			mth.add(AFlag.INCONSISTENT_CODE);
+			LOG.warn("Unexpected end of synchronized block");
+			return null;
+		}
 		BlockNode exit;
 		if (exits.size() == 1) {
 			exit = getNextBlock(exits.iterator().next());
 		} else {
 			cacheSet.clear();
-			exit = traverseMonitorExitsCross(block, exits, cacheSet);
+			exit = traverseMonitorExitsCross(body, exits, cacheSet);
 		}
 
 		stack.push(synchRegion);
 		stack.addExit(exit);
-		synchRegion.getSubBlocks().add(makeRegion(block, stack));
+		synchRegion.getSubBlocks().add(makeRegion(body, stack));
 		stack.pop();
 		return exit;
 	}

jadx-core/src/main/java/jadx/core/utils/AsmUtils.java

@@ -12,9 +12,18 @@ public class AsmUtils {
 	}
 
 	public static String getNameFromClassFile(File file) throws IOException {
-		FileInputStream in = new FileInputStream(file);
+		String className = null;
+		FileInputStream in = null;
+		try {
+			in = new FileInputStream(file);
 			ClassReader classReader = new ClassReader(in);
-		return classReader.getClassName();
+			className = classReader.getClassName();
+		} finally {
+			if (in != null) {
+				in.close();
+			}
+		}
+		return className;
 	}
 
 }

jadx-core/src/main/java/jadx/core/utils/files/InputFile.java

@@ -102,12 +102,24 @@ public class InputFile {
 	private static Dex loadFromClassFile(File file) throws IOException, DecodeException {
 		File outFile = File.createTempFile("jadx-tmp-", System.nanoTime() + ".jar");
 		outFile.deleteOnExit();
-		FileOutputStream out = new FileOutputStream(outFile);
-		JarOutputStream jo = new JarOutputStream(out);
+		FileOutputStream out = null;
+		JarOutputStream jo = null;
+		try {
+			out = new FileOutputStream(outFile);
+			jo = new JarOutputStream(out);
 			String clsName = AsmUtils.getNameFromClassFile(file);
+			if (clsName == null) {
+				throw new IOException("Can't read class name from file: " + file);
+			}
 			FileUtils.addFileToJar(jo, file, clsName + ".class");
+		} finally {
+			if (jo != null) {
 				jo.close();
+			}
+			if (out != null) {
 				out.close();
+			}
+		}
 		return loadFromJar(outFile);
 	}