Move some early-out code to the top of the function

src/common/dcgraph.cpp

@@ -1210,6 +1210,11 @@ void wxGCDCImpl::DoDrawRotatedText(const wxString& text, wxCoord x, wxCoord y,
 
 void wxGCDCImpl::DoDrawText(const wxString& str, wxCoord x, wxCoord y)
 {
+    wxCHECK_RET( IsOk(), "wxGCDC::DoDrawText - invalid DC" );
+
+    if ( str.empty() )
+        return;
+
     // For compatibility with other ports (notably wxGTK) and because it's
     // genuinely useful, we allow passing multiline strings to DrawText().
     // However there is no native OSX function to draw them directly so we
@@ -1222,11 +1227,6 @@ void wxGCDCImpl::DoDrawText(const wxString& str, wxCoord x, wxCoord y)
         return;
     }
 
-    wxCHECK_RET( IsOk(), wxT("wxGCDC(cg)::DoDrawText - invalid DC") );
-
-    if ( str.empty() )
-        return;
-
     // Text drawing shouldn't be affected by the raster operation
     // mode set by SetLogicalFunction() and should be always done
     // in the default wxCOPY mode (which is wxCOMPOSITION_OVER
@@ -1368,6 +1368,9 @@ void wxGCDCImpl::DoGradientFillLinear(const wxRect& rect,
                                   const wxColour& destColour,
                                   wxDirection nDirection )
 {
+    if (rect.width == 0 || rect.height == 0)
+        return;
+
     wxPoint start;
     wxPoint end;
     switch( nDirection)
@@ -1396,9 +1399,6 @@ void wxGCDCImpl::DoGradientFillLinear(const wxRect& rect,
         break;
     }
 
-    if (rect.width == 0 || rect.height == 0)
-        return;
-
     m_graphicContext->SetBrush( m_graphicContext->CreateLinearGradientBrush(
         start.x,start.y,end.x,end.y, initialColour, destColour));
     m_graphicContext->SetPen(*wxTRANSPARENT_PEN);