Fix paths in nested relative includes

Fixes #1321

src/Cryptol/Parser/NoInclude.hs

@@ -196,7 +196,9 @@ resolveInclude lf = pushPath lf $ do
   case parseProgramWith (defaultConfig { cfgSource = thing lf, cfgPreProc = guessPreProc (thing lf) }) source of
 
     Right prog -> do
-      Program ds <- withIncPath (thing lf) (noIncludeProgram prog)
+      Program ds <-
+        do path <- fromIncPath (thing lf)
+           withIncPath path (noIncludeProgram prog)
       return ds
 
     Left err -> M (raise [IncludeParseError err])

tests/modsys/relative-include/A/B/C.cry

@@ -0,0 +1,4 @@
+module A::B::C where
+import A::B::D::E::F
+include "G/H.pcry"  // succeeds when run from `test/`
+

tests/modsys/relative-include/A/B/D/E/F.cry

@@ -0,0 +1,2 @@
+module A::B::D::E::F where
+x = 1

tests/modsys/relative-include/A/B/G/H.pcry

@@ -0,0 +1,2 @@
+y = 2
+include "I.pcry"

tests/modsys/relative-include/A/B/G/I.pcry

@@ -0,0 +1 @@
+z = 3

tests/modsys/relative-include/relative-include.icry

@@ -0,0 +1 @@
+:m A::B::C

tests/modsys/relative-include/relative-include.icry.stdout

@@ -0,0 +1,4 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading module A::B::D::E::F
+Loading module A::B::C