Merge branch 'jonbob/cice/fix-unitialized-variable' (PR #1274)

This PR fixes an uninitialized variable in function FirstFactor in
ice_spacecurve.F90 and adds testing of its returned value in the calling routine.
It resolves Issue #880 , though not exactly in the manner suggested by the
reporter. The uninitialized variable, res, is initialized to 0, which would be an
invalid return value for this variable, because it represents the index of a
particular value in a derived type array.  This function is only called by one
subroutine, so in the calling routine a check is added to make sure the returned
value is valid before using it.

Fixes #880

Tested with SMS_D.f19_f19.FC5.edison_intel

[BFB]

components/cice/src/source/ice_spacecurve.F90

@@ -1139,6 +1139,7 @@ function FirstFactor(fac) result(res)
        integer (int_kind) :: i
 
        found = .false.
+       res = 0
        i=1
        do while (i<=fac%numfact .and. (.not. found))
           if(fac%used(i) == 0) then
@@ -1189,8 +1190,10 @@ subroutine MatchFactor(fac1,fac2,val,found)
 
       val1 = FirstFactor(fac1)
 !JMD      print *,'Matchfactor: found value: ',val1
-      found = FindandMark(fac2,val1,.true.)
-      tmp = FindandMark(fac1,val1,found)
+      if (val1.ge.1) then
+        found = FindandMark(fac2,val1,.true.)
+        tmp = FindandMark(fac1,val1,found)
+      endif
       if (found) then
         val = val1
       else