Fix safe haskell bug: instances in safe-inferred

Instances in Safe Inferred modules weren't marked being marked as coming
from a Safe module.

3 files changed, 23 insertions, 3 deletions

diff --git a/testsuite/tests/safeHaskell/safeInfered/SafeInfered05.stderr b/testsuite/tests/safeHaskell/safeInfered/SafeInfered05.stderr
new file mode 100644
index 0000000000..10e70c409c
--- /dev/null
+++ b/testsuite/tests/safeHaskell/safeInfered/SafeInfered05.stderr
@@ -0,0 +1,19 @@
+
+SafeInfered05.hs:2:14: Warning:
+    -XOverlappingInstances is deprecated: instead use per-instance pragmas OVERLAPPING/OVERLAPPABLE/OVERLAPS
+[1 of 2] Compiling SafeInfered05_A  ( SafeInfered05_A.hs, SafeInfered05_A.o )
+
+SafeInfered05_A.hs:2:16: Warning:
+    ‘SafeInfered05_A’ has been inferred as safe!
+[2 of 2] Compiling SafeInfered05    ( SafeInfered05.hs, SafeInfered05.o )
+
+SafeInfered05.hs:31:9:
+    Unsafe overlapping instances for C [Int] arising from a use of ‘f’
+    The matching instance is:
+      instance [safe] C [Int] -- Defined at SafeInfered05_A.hs:8:10
+    It is compiled in a Safe module and as such can only
+    overlap instances from the same module, however it
+    overlaps the following instances from different modules:
+      instance [overlap ok] C [a] -- Defined at SafeInfered05.hs:27:10
+    In the expression: f ([1, 2, 3, 4] :: [Int])
+    In an equation for ‘test2’: test2 = f ([1, 2, 3, 4] :: [Int])
diff --git a/testsuite/tests/safeHaskell/safeInfered/SafeInfered05_A.hs b/testsuite/tests/safeHaskell/safeInfered/SafeInfered05_A.hs
index a1e12a6526..c9e5c964cb 100644
--- a/testsuite/tests/safeHaskell/safeInfered/SafeInfered05_A.hs
+++ b/testsuite/tests/safeHaskell/safeInfered/SafeInfered05_A.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE FlexibleInstances #-}
+{-# OPTIONS_GHC -fwarn-safe #-}
 module SafeInfered05_A where
 
 class C a where
diff --git a/testsuite/tests/safeHaskell/safeInfered/all.T b/testsuite/tests/safeHaskell/safeInfered/all.T
index 12e80a7fde..9fb4b2c4ea 100644
--- a/testsuite/tests/safeHaskell/safeInfered/all.T
+++ b/testsuite/tests/safeHaskell/safeInfered/all.T
@@ -22,9 +22,9 @@ test('SafeInfered04',
      multimod_compile, ['SafeInfered04', ''])
 
 # Test should fail, tests an earlier bug in 7.8
-# test('SafeInfered05',
-#      [ extra_clean(['SafeInfered05_A.hi', 'SafeInfered05_A.o']) ],
-#      multimod_compile_fail, ['SafeInfered05', ''])
+test('SafeInfered05',
+     [ extra_clean(['SafeInfered05_A.hi', 'SafeInfered05_A.o']) ],
+     multimod_compile_fail, ['SafeInfered05', ''])
 
 # Tests that should fail to compile as they should be infered unsafe
 test('UnsafeInfered01',