error message when column name is 01,02or so on in computed

columns(T55384)

UI/org.eclipse.birt.report.designer.ui.data/src/org/eclipse/birt/report/designer/data/ui/dataset/DataSetComputedColumnsPage.java

@@ -1715,13 +1715,80 @@ && isBlankProperty( txtParams[0].getText( ) ) )
 			}
 			return getOKStatus( );
 		}
-
+
+		/**
+		 * If text is a decimal presentation of int32 value, then text is index.
+		 * In this case return true and make send out error message. Otherwise
+		 * return false means the column name is right.
+		 */		
 		private boolean isNumeric( String text )
 		{
-		    Pattern pattern = Pattern.compile("-[0-9]*|[0-9]*"); 
-		    return pattern.matcher(text).matches(); 
+			long indexTest = indexFromString( text );
+			if ( indexTest >= 0 )
+			{
+				return true;
+			}
+			return false;
 		}
 
+		private long indexFromString( String str )
+		{
+			// The length of the decimal string representation of
+			// Integer.MAX_VALUE, 2147483647
+			final int MAX_VALUE_LENGTH = 10;
+
+			int len = str.length( );
+			if ( len > 0 )
+			{
+				int i = 0;
+				boolean negate = false;
+				int c = str.charAt( 0 );
+				if ( c == '-' )
+				{
+					if ( len > 1 )
+					{
+						c = str.charAt( 1 );
+						i = 1;
+						negate = true;
+					}
+				}
+				c -= '0';
+				if ( 0 <= c
+						&& c <= 9
+						&& len <= ( negate ? MAX_VALUE_LENGTH + 1
+								: MAX_VALUE_LENGTH ) )
+				{
+					// Use negative numbers to accumulate index to handle
+					// Integer.MIN_VALUE that is greater by 1 in absolute value
+					// then Integer.MAX_VALUE
+					int index = -c;
+					int oldIndex = 0;
+					i++;
+					if ( index != 0 )
+					{
+						// Note that 00, 01, 000 etc. are not indexes
+						while ( i != len
+								&& 0 <= ( c = str.charAt( i ) - '0' ) && c <= 9 )
+						{
+							oldIndex = index;
+							index = 10 * index - c;
+							i++;
+						}
+					}
+					// Make sure all characters were consumed and that it
+					// couldn't
+					// have overflowed.
+					if ( i == len
+							&& ( oldIndex > ( Integer.MIN_VALUE / 10 ) || ( oldIndex == ( Integer.MIN_VALUE / 10 ) && c <= ( negate
+									? -( Integer.MIN_VALUE % 10 )
+									: ( Integer.MAX_VALUE % 10 ) ) ) ) )
+					{
+						return 0xFFFFFFFFL & ( negate ? index : -index );
+					}
+				}
+			}
+			return -1L;
+		}
 		private boolean checkExpressionBindingFields( ) throws BirtException
 		{
 			for ( int i = 0; i < txtParams.length; i++ )