Patch by ahenriksson to fix a computation bug in Deskcalc

Ticket #8389 Signed off by John Scipione

When trimming trailing 0's to make the number fit in the window,
make sure to only trim trailing 0's AFTER the decimal point, not before.

src/apps/deskcalc/ExpressionTextView.cpp

@@ -258,7 +258,7 @@ ExpressionTextView::SetValue(BString value)
 			stringWidth = font.StringWidth(value);
 		}
 
-		// there is no need to keep the period if no digits follow
+		// no need to keep the period if no digits follow
 		if (value[offset] == '.') {
 			value.Remove(offset, 1);
 			offset--;
@@ -273,7 +273,7 @@ ExpressionTextView::SetValue(BString value)
 				digit = (int)(value[offset]) - '0' + 1; // ascii to int + 1
 				if (digit != 10)
 					break;
-				value.Remove(offset, 1);
+				value[offset] = '0';
 			}
 			if (digit == 10) {
 				// carry over, shift the result
@@ -296,16 +296,26 @@ ExpressionTextView::SetValue(BString value)
 			} else {
 				// increase the current digit value with one
 				value[offset] = char(digit + 48);
+
+				// set offset to last digit
+				offset = value.FindFirst('E');
+				if (offset == B_ERROR)
+					offset = value.CountChars();
+				offset--;
 			}
 		}
 
-		// remove trailing zeros
-		while (value[offset] == '0')
-			value.Remove(offset--, 1);
+		// clean up decimal part if we have one
+		if (value.FindFirst('.') != B_ERROR) {
+			// remove trailing zeros
+			while (value[offset] == '0')
+				value.Remove(offset--, 1);
 
-		// there is no need to keep the period if no digits follow
-		if (value[offset] == '.')
-			value.Remove(offset, 1);
+			// there is no need to keep the period if no 
+			// digits follow
+			if (value[offset] == '.')
+				value.Remove(offset, 1);
+		}
 	}
 
 	// set the new value