added an error detection for missing imaginary character while parsing complex string

JIRA: MATH-198

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@640191 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/complex/ComplexFormat.java

@@ -374,7 +374,9 @@ public class ComplexFormat extends Format implements Serializable {
         int n = getImaginaryCharacter().length();
         startIndex = pos.getIndex();
         int endIndex = startIndex + n;
-        if (source.substring(startIndex, endIndex).compareTo(
+        if ((startIndex >= source.length()) ||
+            (endIndex > source.length()) ||
+            source.substring(startIndex, endIndex).compareTo(
             getImaginaryCharacter()) != 0) {
             // set index back to initial, error index should be the start index
             // character examined.

src/site/xdoc/changes.xml

@@ -44,6 +44,9 @@ Commons Math Release Notes</title>
       <action dev="brentworden" type="fix" issue="MATH-193" due-to="Michael Heuer and Sebb">
         Javadoc and style fixes.
       </action>
+      <action dev="luc" type="fix" issue="MATH-198" due-to="Frederick Salardi">
+        added an error detection for missing imaginary character while parsing complex string
+      </action>
     </release>
     <release version="1.2" date="2008-02-24"
     description="This release combines bug fixes and new features. Most notable

src/test/org/apache/commons/math/complex/ComplexFormatAbstractTest.java

@@ -19,6 +19,7 @@ package org.apache.commons.math.complex;
 
 import java.text.NumberFormat;
 import java.text.ParseException;
+import java.text.ParsePosition;
 import java.util.Locale;
 
 import junit.framework.TestCase;
@@ -348,4 +349,10 @@ public abstract class ComplexFormatAbstractTest extends TestCase {
             // success
         }
     }
+
+    public void testForgottenImaginaryCharacter() {
+        ParsePosition pos = new ParsePosition(0);
+        assertNull(new ComplexFormat().parse("1 + 1", pos));
+        assertEquals(5, pos.getErrorIndex());
+    }
 }