[commit: packages/hpc] wip/T9619: Allow same `Mix` file in different dirs (#9619) (6857115)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/hpc

On branch  : wip/T9619
Link       : http://git.haskell.org/packages/hpc.git/commitdiff/6857115fb24862cb5ac11615fe14849dc869f42f

>---------------------------------------------------------------

commit 6857115fb24862cb5ac11615fe14849dc869f42f
Author: Thomas Miedema <thomasmiedema at gmail.com>
Date:   Thu Mar 5 21:43:36 2015 +0100

    Allow same `Mix` file in different dirs (#9619)


>---------------------------------------------------------------

6857115fb24862cb5ac11615fe14849dc869f42f
 Trace/Hpc/Mix.hs                               | 12 ++++++++----
 tests/simple/tixs/{.hpc => .hpc.copy}/Main.mix |  0
 tests/simple/tixs/test.T                       |  4 ++++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/Trace/Hpc/Mix.hs b/Trace/Hpc/Mix.hs
index 4a7fc74..f4025d9 100644
--- a/Trace/Hpc/Mix.hs
+++ b/Trace/Hpc/Mix.hs
@@ -49,7 +49,7 @@ data Mix = Mix
              Hash               -- hash of mix entry + timestamp
              Int                -- tab stop value.
              [MixEntry]         -- entries
-        deriving (Show,Read)
+        deriving (Show,Read,Eq)
 
 type MixEntry = (HpcPos, BoxLabel)
 
@@ -104,9 +104,13 @@ readMix dirNames mod' = do
                    | dirName <- dirNames
                    ]
    case catMaybes res of
-     [r] -> return r
-     xs@(_:_) -> error $ "found " ++ show(length xs) ++ " instances of " ++ modName ++ " in " ++ show dirNames
-     _        -> error $ "can not find " ++ modName ++ " in " ++ show dirNames
+     xs@(x:_:_) | any (/= x) (tail xs) ->
+              -- Only complain if multiple *different* `Mix` files with the
+              -- same name are found (#9619).
+              error $ "found " ++ show(length xs) ++ " different instances of "
+                      ++ modName ++ " in " ++ show dirNames
+     (x:_) -> return x
+     _     -> error $ "can not find " ++ modName ++ " in " ++ show dirNames
 
 mixName :: FilePath -> String -> String
 mixName dirName name = dirName </> name <.> "mix"
diff --git a/tests/simple/tixs/.hpc/Main.mix b/tests/simple/tixs/.hpc.copy/Main.mix
similarity index 100%
copy from tests/simple/tixs/.hpc/Main.mix
copy to tests/simple/tixs/.hpc.copy/Main.mix
diff --git a/tests/simple/tixs/test.T b/tests/simple/tixs/test.T
index 48ca67f..8e98d0e 100644
--- a/tests/simple/tixs/test.T
+++ b/tests/simple/tixs/test.T
@@ -67,3 +67,7 @@ test('hpc_hand_overlay',
       "{hpc} report total3.tix"])
 
 test('hpc_bad_001', exit_code(1), run_command, ["{hpc} bad arguments"])
+
+test('T9619', ignore_output, run_command,
+     # Having the same mix file in two different hpcdirs should work.
+     ["{hpc} report hpc_sample.tix --hpcdir=.hpc --hpcdir=.hpc.copy"])