Convert empty string to null Enum value, only throw ConversionExceptions (#14756)

Change-Id: I027a245975db12e3661740bd233edd98e73994e9

4 files changed, 30 insertions, 12 deletions

diff --git a/server/src/com/vaadin/data/util/converter/StringToEnumConverter.java b/server/src/com/vaadin/data/util/converter/StringToEnumConverter.java
index a1328d831c..29bf8fc400 100644
--- a/server/src/com/vaadin/data/util/converter/StringToEnumConverter.java
+++ b/server/src/com/vaadin/data/util/converter/StringToEnumConverter.java
@@ -34,7 +34,7 @@ public class StringToEnumConverter implements Converter<String, Enum> {
     @Override
     public Enum convertToModel(String value, Class<? extends Enum> targetType,
             Locale locale) throws ConversionException {
-        if (value == null) {
+        if (value == null || value.trim().equals("")) {
             return null;
         }
         if (locale == null) {
@@ -46,19 +46,21 @@ public class StringToEnumConverter implements Converter<String, Enum> {
         String result = value.replace(" ", "_").toUpperCase(locale);
         try {
             return Enum.valueOf(targetType, result);
-        } catch (IllegalArgumentException ee) {
+        } catch (Exception ee) {
             // There was no match. Try to compare the available values to see if
             // the constant is using something else than all upper case
-
-            EnumSet<?> set = EnumSet.allOf(targetType);
-            for (Enum e : set) {
-                if (e.name().toUpperCase(locale).equals(result)) {
-                    return e;
+            try {
+                EnumSet<?> set = EnumSet.allOf(targetType);
+                for (Enum e : set) {
+                    if (e.name().toUpperCase(locale).equals(result)) {
+                        return e;
+                    }
                 }
+            } catch (Exception e) {
             }
 
-            // Fallback did not work either, re-throw original exception so user
-            // knows what went wrong
+            // Fallback did not work either, re-throw original exception so
+            // user knows what went wrong
             throw new ConversionException(ee);
         }
     }
diff --git a/server/tests/src/com/vaadin/tests/data/converter/TestStringToEnumConverter.java b/server/tests/src/com/vaadin/tests/data/converter/TestStringToEnumConverter.java
index 2b19395c08..5dc24ca43a 100644
--- a/server/tests/src/com/vaadin/tests/data/converter/TestStringToEnumConverter.java
+++ b/server/tests/src/com/vaadin/tests/data/converter/TestStringToEnumConverter.java
@@ -3,6 +3,7 @@ package com.vaadin.tests.data.converter;
 import junit.framework.TestCase;
 
 import com.vaadin.data.util.converter.Converter;
+import com.vaadin.data.util.converter.Converter.ConversionException;
 import com.vaadin.data.util.converter.ReverseConverter;
 import com.vaadin.data.util.converter.StringToEnumConverter;
 
@@ -16,6 +17,19 @@ public class TestStringToEnumConverter extends TestCase {
     Converter<Enum, String> reverseConverter = new ReverseConverter<Enum, String>(
             converter);
 
+    public void testEmptyStringConversion() {
+        assertEquals(null, converter.convertToModel("", Enum.class, null));
+    }
+
+    public void testInvalidEnumClassConversion() {
+        try {
+            converter.convertToModel("Foo", Enum.class, null);
+            fail("No exception thrown");
+        } catch (ConversionException e) {
+            // OK
+        }
+    }
+
     public void testNullConversion() {
         assertEquals(null, converter.convertToModel(null, Enum.class, null));
     }
diff --git a/uitest/src/com/vaadin/tests/components/textfield/EnumTextField.java b/uitest/src/com/vaadin/tests/components/textfield/EnumTextField.java
index 67b3b84688..99e08ae32d 100644
--- a/uitest/src/com/vaadin/tests/components/textfield/EnumTextField.java
+++ b/uitest/src/com/vaadin/tests/components/textfield/EnumTextField.java
@@ -31,6 +31,7 @@ public class EnumTextField extends AbstractTestUIWithLog {
     @Override
     protected void setup(VaadinRequest request) {
         final TextField tf = new TextField();
+        tf.setNullRepresentation("");
         tf.addValueChangeListener(new ValueChangeListener() {
 
             @Override
diff --git a/uitest/src/com/vaadin/tests/components/textfield/EnumTextFieldTest.java b/uitest/src/com/vaadin/tests/components/textfield/EnumTextFieldTest.java
index 113acee3a2..fe26fb7aad 100644
--- a/uitest/src/com/vaadin/tests/components/textfield/EnumTextFieldTest.java
+++ b/uitest/src/com/vaadin/tests/components/textfield/EnumTextFieldTest.java
@@ -27,8 +27,7 @@ public class EnumTextFieldTest extends SingleBrowserTest {
     public void validValues() {
         openTestURL();
         $(TextFieldElement.class).first().clear();
-        $(TextFieldElement.class).first().sendKeys("Value");
-        $(TextFieldElement.class).first().sendKeys(Keys.TAB);
+        $(TextFieldElement.class).first().sendKeys("Value", Keys.TAB);
         Assert.assertEquals("3. Value (valid)", getLogRow(0));
 
         $(TextFieldElement.class).first().clear();
@@ -41,13 +40,15 @@ public class EnumTextFieldTest extends SingleBrowserTest {
         $(TextFieldElement.class).first().sendKeys(Keys.TAB);
         Assert.assertEquals("7. The last value (valid)", getLogRow(0));
 
+        $(TextFieldElement.class).first().clear();
+        Assert.assertEquals("8. null (valid)", getLogRow(0));
+
     }
 
     @Test
     public void invalidValue() {
         openTestURL();
         $(TextFieldElement.class).first().clear();
-        Assert.assertEquals("2. (INVALID)", getLogRow(0));
 
         $(TextFieldElement.class).first().sendKeys("bar");
         $(TextFieldElement.class).first().sendKeys(Keys.TAB);