When using Label in an ItemRenderer and setting paddingLeft and width, the maxDisplayedLines throws an error.

Hopefully I'm explaining this clearly enough... Let me know if there's anything else you need.

Steps to reproduce:
1. Define custom ItemRenderer for a list.
2. CustomItemRenderer has label inside
3. Label is 100% by 100% (height/width)
4. Label has paddingLeft set to any non-zero value
5. Label has maxDisplayedLines set to any non-zero value

Actual Results:
RangeError: Error #1125: The index -1 is out of range 0.
at spark.components::Label/computeLastAllowedLineIndex()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\Label.as:1276]
at spark.components::Label/truncateText()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\Label.as:1149]
at spark.components::Label/http://www.adobe.com/2006/flex/mx/internal::composeTextLines()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\Label.as:435]
at spark.components.supportClasses::TextBase/updateDisplayList()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\supportClasses\TextBase.as:570]
at mx.core::UIComponent/validateDisplayList()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\core\UIComponent.as:8065]
at mx.managers::LayoutManager/validateClient()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\managers\LayoutManager.as:931]
at mx.core::UIComponent/validateNow()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\core\UIComponent.as:7249]
at spark.components::DataGroup/initializeTypicalItem()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\DataGroup.as:247]
at spark.components::DataGroup/ensureTypicalLayoutElement()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\DataGroup.as:266]
at spark.components::DataGroup/measure()[E:\dev\gumbo_beta2\frameworks\projects\spark\src\spark\components\DataGroup.as:1038]
at mx.core::UIComponent/measureSizes()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\core\UIComponent.as:7580]
at mx.core::UIComponent/validateSize()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\core\UIComponent.as:7504]
at mx.managers::LayoutManager/validateSize()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\managers\LayoutManager.as:617]
at mx.managers::LayoutManager/doPhasedInstantiation()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\managers\LayoutManager.as:733]
at mx.managers::LayoutManager/doPhasedInstantiationCallback()[E:\dev\gumbo_beta2\frameworks\projects\framework\src\mx\managers\LayoutManager.as:1069]

Expected Results:
Padding and setting of maxDisplayedLines to not cause runtime error.

Workaround (if any):
Explicitly set left instead of using padding. And must use a background rect to fill desired gap with correct color instead of relying on label background color.