Fix #10493.
authorRichard Eisenberg <eir@cis.upenn.edu>
Mon, 8 Jun 2015 20:46:46 +0000 (16:46 -0400)
committerRichard Eisenberg <eir@cis.upenn.edu>
Tue, 16 Jun 2015 18:22:51 +0000 (14:22 -0400)
commitace8d4fcfd798b70c34e325c562878b0a8f5e2cb
tree0ef69e5d9fbce1be11d2219055d1d0a4405f85da
parent0de0b14691e0b0789988332ad5addc2a31b09ba6
Fix #10493.

Now, a Coercible (T1 ...) (T2 ...) constraint is insoluble only
when both T1 and T2 say "yes" to isDistinctTyCon. Several comments
also updated in this patch.
compiler/typecheck/TcCanonical.hs
compiler/types/TyCon.hs
compiler/types/Unify.hs
testsuite/tests/typecheck/should_compile/T10493.hs [new file with mode: 0644]
testsuite/tests/typecheck/should_compile/all.T