Updated cache logic to be exception-safe.

src/io/nayuki/fastqrcodegen/QrTemplate.java

@@ -57,13 +57,18 @@ final class QrTemplate {
 			}
 		}
 		
-		QrTemplate tpl = new QrTemplate(version);
+		try {
-		synchronized(cache) {
+			QrTemplate tpl = new QrTemplate(version);
-			cache[version] = new SoftReference<>(tpl);
+			synchronized(cache) {
-			isPending[version] = false;
+				cache[version] = new SoftReference<>(tpl);
-			cache.notifyAll();
+			}
+			return tpl;
+		} finally {
+			synchronized(cache) {
+				isPending[version] = false;
+				cache.notifyAll();
+			}
 		}
-		return tpl;
 	}
 	
 	

src/io/nayuki/fastqrcodegen/ReedSolomonGenerator.java

@@ -59,13 +59,18 @@ final class ReedSolomonGenerator {
 			}
 		}
 		
-		ReedSolomonGenerator rs = new ReedSolomonGenerator(degree);
+		try {
-		synchronized(cache) {
+			ReedSolomonGenerator rs = new ReedSolomonGenerator(degree);
-			cache[degree] = new SoftReference<>(rs);
+			synchronized(cache) {
-			isPending[degree] = false;
+				cache[degree] = new SoftReference<>(rs);
-			cache.notifyAll();
+			}
+			return rs;
+		} finally {
+			synchronized(cache) {
+				isPending[degree] = false;
+				cache.notifyAll();
+			}
 		}
-		return rs;
 	}