fix wrong sign for overlap distance in last checkin

git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@281 f88db872-0e4f-0410-b76b-b9085cfa78c5

1 files changed, 7 insertions, 3 deletions

diff --git a/src/patch/ghost_zone.cc b/src/patch/ghost_zone.cc
index 327182f..10ac5ee 100644
--- a/src/patch/ghost_zone.cc
+++ b/src/patch/ghost_zone.cc
@@ -228,10 +228,14 @@ if (! (    (common_coords_set == my_edge().coords_set_perp())
 								/*NOTREACHED*/
 
 // perp coordinate must match (mod 2*pi) across the two patches
+// after taking into account any overlap
 const fp other_overlap = N_overlap_points * other_edge().perp_map().delta_fp();
-const fp other_outer_perp = other_edge().grid_outer_perp()
-			    + (other_edge().is_min() ? - other_overlap
-						     : + other_overlap);
+const fp other_outer_perp_minus_overlap	// move back inwards into other patch
+					// by overlap distance, to get a value
+					// that should match our own
+					// grid_outer_perp() value
+	= other_edge().grid_outer_perp()
+	  + (other_edge().is_min() ? + other_overlap : - other_overlap);
 if (! local_coords::fuzzy_EQ_ang(my_edge().grid_outer_perp(), other_outer_perp))
    then error_exit(ERROR_EXIT,
 "***** interpatch_ghost_zone::interpatch_ghost_zone:\n"