Bugfix Tools::CodeView2::GutterView - do not redraw gutter if its not shown.
This actually fixes DNU when CodeView2 is used in diff view. Then the
second gutter is not shown and #yOfTextViewLine: returns nil (bad) which
leads to DNU.
*.H
*.STH
notes
makefile
libcomp.*
.listOfSTfiles
.dependencies
*.obj
*.ilk
*.dll
*.lib
*.pdb
*.sbr
*.c
*.sc
*.xc
so_locations
classList.stc
objbc
objvc
objmingw
*.@@@
*.res
*.RES
*.map