errors: restructure formatparse() to clarify conditions a bit

The `similar` list will be calculated only for
`error.UnknownIdentifier`. It was then printed only if `inst.location
is None`, which is true for that exception type, but it's an indirect
condition to rely on.

Also, it looked from the code like it could both report similarities
and print a hint. That would be a little awkward because the
similarity report looks similar to the hint (both are printed within
parentheses). I also added a `elif` to clarify that. I plan to
refactor this more coming patches so the similarity report actually is
a hint.

Differential Revision: https://phab.mercurial-scm.org/D9343

mercurial/scmutil.py

@@ -159,10 +159,6 b' def reportsimilar(write, similar):'
 
 
 def formatparse(write, inst):
-    similar = []
-    if isinstance(inst, error.UnknownIdentifier):
-        # make sure to check fileset first, as revset can invoke fileset
-        similar = getsimilar(inst.symbols, inst.function)
     if inst.location is not None:
         write(
             _(b"hg: parse error at %s: %s\n")
@@ -170,8 +166,11 b' def formatparse(write, inst):'
         )
     else:
         write(_(b"hg: parse error: %s\n") % inst.message)
+    if isinstance(inst, error.UnknownIdentifier):
+        # make sure to check fileset first, as revset can invoke fileset
+        similar = getsimilar(inst.symbols, inst.function)
         reportsimilar(write, similar)
-    if inst.hint:
+    elif inst.hint:
         write(_(b"(%s)\n") % inst.hint)