Add reproduction case for #1342

Signed-off-by: Jeremie Dimino <[email protected]>

Author: jeremiedimino

test/blackbox-tests/dune.inc

@@ -279,6 +279,14 @@
    test-cases/github1231
    (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected)))))
 
+(alias
+ (name github1342)
+ (deps (package dune) (source_tree test-cases/github1342))
+ (action
+  (chdir
+   test-cases/github1342
+   (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected)))))
+
 (alias
  (name github20)
  (deps (package dune) (source_tree test-cases/github20))
@@ -977,6 +985,7 @@
   (alias github1019)
   (alias github1099)
   (alias github1231)
+  (alias github1342)
   (alias github20)
   (alias github24)
   (alias github25)
@@ -1092,6 +1101,7 @@
   (alias github1019)
   (alias github1099)
   (alias github1231)
+  (alias github1342)
   (alias github20)
   (alias github24)
   (alias github25)

test/blackbox-tests/test-cases/github1342/run.t

@@ -0,0 +1,11 @@
+Reproduction case for #1342. Check that when the user edits files in
+_build, things are rebuild as expected.
+
+  $ echo 42 > x
+  $ dune build x
+  $ cat _build/default/x
+  42
+  $ echo 0 > _build/default/x
+  $ dune build x
+  $ cat _build/default/x
+  0