fix logic in SE interpolate_vector routines

doc/ChangeLog

@@ -3,7 +3,7 @@
 Tag name:
 Originator(s): jedwards, eaton
 Date:
-One-line Summary: fix issues #1108, #1106, #1058; merge PR#1101
+One-line Summary: fix issues #1108, #1106, #1058, #1051; merge PR#1101
 Github PR URL: https://github.com/ESCOMP/CAM/pull/1131
 
 Purpose of changes (include the issue number and title text for each relevant GitHub issue):
@@ -31,6 +31,11 @@ Issue #1058 - Remove unused pbuf variable smaw
   remains.  It is used locally, and may be written to history file
   (UW_turbtype).
 
+Issue #1051 - Bad logic in SE dycore "interpolate_vector" subroutines
+- These subroutines are not currently used by CAM as they are restricted to
+  interpolating fields on the GLL grid.  Fix the conditional logic and
+  update the endrun message.
+
 
 Describe any changes made to build system:
 
@@ -65,6 +70,11 @@ src/control/cam_snapshot_common.F90
 . fill_pbuf_info
   - remove smaw, turbtype
 
+src/dynamics/se/dycore/interpolate_mod.F90
+. interpolate_vector2d and interpolate_vector3d
+  - fix conditional logic and clarify endrun message to indicate that the
+    input fields must be on the GLL grid.
+
 src/physics/cam/eddy_diff.F90
 . caleddy
   - remove intent(out) arg sm_aw

src/dynamics/se/dycore/interpolate_mod.F90

@@ -1625,8 +1625,8 @@ subroutine interpolate_vector2d(interpdata,elem,fld_cube,npts,fld,input_coords,
 
     if (npts==np) then
        interp => interp_p
-    else if (npts==np) then
-       call endrun('interpolate_vector2d: Error in interpolate_vector(): input must be on velocity grid')
+    else
+       call endrun('interpolate_vector2d: Error in interpolate_vector(): input must be on GLL grid')
     endif
 
 
@@ -1715,8 +1715,8 @@ subroutine interpolate_vector3d(interpdata,elem,fld_cube,npts,nlev,fld,input_coo
 
     if (npts==np) then
        interp => interp_p
-    else if (npts==np) then
-       call endrun('interpolate_vector3d: Error in interpolate_vector(): input must be on velocity grid')
+    else
+       call endrun('interpolate_vector3d: Error in interpolate_vector(): input must be on GLL grid')
     endif