filemerge: pass a default value to _toolstr (issue5718)
After a refactoring, _toolstr stopped having default="" as one of it's args,
therefore when called without a default it returns None and not "". This causes
concatenation to fail.
--- a/mercurial/filemerge.py Tue Oct 31 06:39:38 2017 +0530
+++ b/mercurial/filemerge.py Thu Oct 26 11:07:06 2017 -0700
@@ -116,7 +116,7 @@
continue
p = util.lookupreg(k, _toolstr(ui, tool, "regname"))
if p:
- p = util.findexe(p + _toolstr(ui, tool, "regappend"))
+ p = util.findexe(p + _toolstr(ui, tool, "regappend", ""))
if p:
return p
exe = _toolstr(ui, tool, "executable", tool)