Fix computation of dfun_tvs in mkNewTypeEqn
authorSimon Peyton Jones <simonpj@microsoft.com>
Tue, 21 Feb 2017 13:29:16 +0000 (13:29 +0000)
committerSimon Peyton Jones <simonpj@microsoft.com>
Tue, 21 Feb 2017 14:26:57 +0000 (14:26 +0000)
commit713ebd7cf03876c6bedc1be9fba8f60ccc5bc8f0
tree8aa42a785d1ea8ee84b69ca091c09ac4ef8d6aba
parentfd841f877ab7a991f667a50b401404927f6f599c
Fix computation of dfun_tvs in mkNewTypeEqn

This bug was causing Trac #13297.

We were recomputing ds_tvs, and doing it wrongly (by omitting
variables that appear only in mtheta).  But actually plain 'tvs'
is just fine.  So code deleted, and bug fixed.
compiler/typecheck/TcDeriv.hs
testsuite/tests/deriving/should_compile/T13297.hs [new file with mode: 0644]
testsuite/tests/deriving/should_compile/all.T