CComponentsHeader: optimize auto size mode for logos

With very large font size settings it is possible
that header is too large for reasonable display of logos, because of
possible bad upscale effects (eg. step effects).
So it seems it's better to use original size as largest possible size.

src/gui/components/cc_frm_header.cpp

@@ -281,6 +281,14 @@ void CComponentsHeader::initLogo()
 	else
 		cch_logo_obj->setChannel(cch_logo.Id, cch_logo.Name);
 
+	//ensure logo is not larger than original size if in auto mode
+	if (cch_logo.dy_max == -1){
+		int dx_orig = 0, dy_orig = 0 ;
+		cch_logo_obj->getRealSize(&dx_orig, &dy_orig);
+		if (cch_logo.dy_max > dy_orig)
+			cch_logo.dy_max = dy_orig;
+	}
+
 	if (cch_logo_obj->hasLogo()){
 		cch_logo_obj->setHeight(cch_logo.dy_max, true);
 

src/gui/components/cc_frm_header.h

@@ -319,6 +319,7 @@ class CComponentsHeader : public CComponentsForm, public CCTextScreen
 		* 		CC_LOGO_RIGHT \n
 		* @param[in]  	dy
 		* 		@li optional logo height, default = -1 (auto)
+		* @note 	In auto mode, logo use full height minus inner offset but not larger than original logo height.
 		*/
 		void setChannelLogo(	const uint64_t& channelId,
 					const std::string& channelName,