Merged revision(s) 21803 from trunk/OpenMPT:

[Mod] S3M: Only ignore O00 effects if the file has been identified as being made with ST3.00/ST3.01. Several other tools identify as ST3.01 but they probably don't need this quirk (in particular UNMO3).
........


git-svn-id: https://source.openmpt.org/svn/openmpt/branches/OpenMPT-1.31@21804 56274372-70c3-4bfc-bfc3-4c3a0b034d27

soundlib/Load_s3m.cpp

@@ -724,7 +724,7 @@ bool CSoundFile::ReadS3M(FileReader &file, ModLoadingFlags loadFlags)
 						else if(m.param > 0x08)
 							zxxCountRight++;
 					}
-				} else if(m.command == CMD_OFFSET && m.param == 0 && fileHeader.cwtv <= S3MFileHeader::trkST3_01)
+				} else if(m.command == CMD_OFFSET && m.param == 0 && isST3 && fileHeader.cwtv <= S3MFileHeader::trkST3_01)
 				{
 					// Offset command didn't have effect memory in ST3.01; fixed in ST3.03
 					m.command = CMD_DUMMY;