Look inside implications in simplifyRule
authorSimon Peyton Jones <simonpj@microsoft.com>
Wed, 31 Jan 2018 14:25:50 +0000 (14:25 +0000)
committerSimon Peyton Jones <simonpj@microsoft.com>
Wed, 31 Jan 2018 14:27:59 +0000 (14:27 +0000)
commite9ae0cae9eb6a340473b339b5711ae76c6bdd045
treeac45bed2f2371df0681f40433ebe7c072a9393c2
parentefba054640d3418d7477316ae0c1e992d0aa0f22
Look inside implications in simplifyRule

Trac #14732 was a perpelexing bug in which -fdefer-typed-holes
caused a mysterious type error in a RULE.  This turned out to
be because we are more aggressive about creating implications
when deferring (see TcUnify.implicationNeeded), and the rule
mechanism hadn't caught up.

This fixes it.
compiler/typecheck/TcRules.hs
testsuite/tests/typecheck/should_compile/T14732.hs [new file with mode: 0644]
testsuite/tests/typecheck/should_compile/all.T