[Fix] MIDI Macros: An unfinished byte right before a "s" SysEx checks…

…um macro letter was not considered in the checksum.

git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@22424 56274372-70c3-4bfc-bfc3-4c3a0b034d27

soundlib/MIDIMacroParser.cpp

@@ -233,6 +233,12 @@ MIDIMacroParser::MIDIMacroParser(const CSoundFile &sndFile, PlayState *playState
 		} else if(macro[pos] == 's')
 		{
 			// SysEx Checksum (not an original Impulse Tracker macro variable, but added for convenience)
+			if(!firstNibble)  // From MIDI.TXT: '9n' is exactly the same as '09 n' or '9 n' -- so finish current byte first
+			{
+				outPos++;
+				firstNibble = true;
+			}
+
 			auto startPos = outPos;
 			while(startPos > 0 && out[--startPos] != 0xF0)
 				;