The GetLegendGraphics request generate a white image if name is empty

Using the last trunk:
if set CLASS name = "" the image is empty and white.
Instead it is correctly create if the name is valorized.

As example:

this will get an empty getlegendgraphics image:

<pre>
LAYER
    NAME "test1"
    TYPE LINE
    STATUS OFF
    EXTENT  1660351.00 4458445.22 1866743.13 4960849.91
    FEATURE
	WKT "LINESTRING(1662120.546188 4858603.677291, 1662738.746295 4858875.082216, 1663854.522097 4858618.755342, 1664779.309249 4858638.85941)"
    END #FEATURE
    METADATA
      "wms_title" "Test"
      "ows_enable_request" "*"
    END
    LABELCACHE on
    CLASS
      name ""
      STYLE
        COLOR 200 0 0
        OUTLINECOLOR 0 255 0
      END
    END #CLASS
  END 
</pre>

Instead this other will generate a correct getlegendgraphic image.

<pre>
LAYER
    NAME "test1"
    TYPE LINE
    STATUS OFF
    EXTENT  1660351.00 4458445.22 1866743.13 4960849.91
    FEATURE
	WKT "LINESTRING(1662120.546188 4858603.677291, 1662738.746295 4858875.082216, 1663854.522097 4858618.755342, 1664779.309249 4858638.85941)"
    END #FEATURE
    METADATA
      "wms_title" "Test"
      "ows_enable_request" "*"
    END
    LABELCACHE on
    CLASS
      name "aaaa"
      STYLE
        COLOR 200 0 0
        OUTLINECOLOR 0 255 0
      END
    END #CLASS
  END 
</pre>