merge: when --tool is specified, disable HGMERGE by setting to empty string...
merge: when --tool is specified, disable HGMERGE by setting to empty string
HGMERGE has different semantics than ui.merge. HGMERGE should hold the name
on an executable in your path, or an absolute tool path. As such, it's not
safe to simply copy the user's specified --tool value into HGMERGE. Instead,
we disable HGMERGE by setting it to an empty string.