Add tests for issue #493 fixed by PR #495

 Ensures no regressions of #493 are encountered when slicing multi-
 codimensioned coarrays

Author: zbeekman

CMakeLists.txt

@@ -760,6 +760,8 @@ if(opencoarrays_aware_compiler)
   # Fixed GCC 7 regressions, should run on GCC 6 and 7
   add_caf_test(static_event_post_issue_293 3 static_event_post_issue_293)
 
+  add_caf_test(issue-493-coindex-slice 8 issue-493-coindex-slice) # Contributed by @neok-m4700 in #493
+
   # These co_reduce (#172, fixed by PR #332, addl discussion in PR
   # #331) tests are for bugs not regressions. Should be fixed in all
   # version of GCC, I beleive

src/tests/regression/reported/CMakeLists.txt

@@ -3,6 +3,7 @@ caf_compile_executable(co_reduce-factorial-int8 issue-172-wrong-co_reduce-int8.f
 caf_compile_executable(co_reduce-factorial-int64 issue-172-wrong-co_reduce-int64.f90)
 caf_compile_executable(source-alloc-sync issue-243-source-allocation-no-sync.f90)
 caf_compile_executable(convert-before-put issue-292-convert-type-before-put.f90)
+caf_compile_executable(issue-493-coindex-slice issue-493-coindex-slice.f90)
 caf_compile_executable(issue-422-send issue-422-send.F90)
 caf_compile_executable(issue-422-send-get issue-422-send-get.F90)
 caf_compile_executable(issue-488-multi-dim-cobounds issue-488-multi-dim-cobounds.f90)

src/tests/regression/reported/issue-493-coindex-slice.f90

@@ -0,0 +1,51 @@
+program slice
+   type coarr
+      real, allocatable :: a(:, :, :)[:, :, :]
+   end type
+
+   type(coarr) :: co
+   integer :: nimg, me, z, nx, ny, nz, north, south, mex, mey, mez, coords(3)
+   real, allocatable :: bufxz(:, :) ! a plane (2d) slice, normal in the y direction
+
+   nx = 6
+   ny = 4
+   nz = 2
+
+   me = this_image()
+   nimg = num_images()
+
+   if (nimg /= 8) stop
+
+   allocate(co % a(nx, ny, nz)[1:2, 1:2, *])
+   allocate(bufxz(nx, nz))
+
+   co % a = reshape([(z, z=1, nx * ny * nz)], shape(co % a))
+
+   coords = this_image(co % a)
+   mex = coords(1)
+   mey = coords(2)
+   mez = coords(3)
+
+   north = mey + 1
+   south = mey - 1
+
+   sync all
+   if (north <= 2) then
+      z = image_index(co % a, [mex, north, mez])
+      sync images(z)
+      bufxz = co % a(1:nx, 1, 1:nz)[mex, north, mez]
+      co % a(1:nx, ny, 1:nz) = bufxz
+   end if
+   if (south >= 1) then
+      z = image_index(co % a, [mex, south, mez])
+      sync images(z)
+      bufxz = co % a(1:nx, 1, 1:nz)[mex, south, mez]
+      co % a(1:nx, ny, 1:nz) = bufxz
+   end if
+   sync all
+
+   deallocate(co % a, bufxz)
+   if(this_image() == 1) write(*,*) "Test passed."
+   ! Regression would cause error message:
+   ! Fortran runtime error on image <...>: libcaf_mpi::caf_get_by_ref(): rank out of range.
+ end program