[gnumeric] Derivatives: fix debug output.

[Morten Welinder <mortenw src gnome org>]

commit f6fb75f181df4f49096c21759cdd1921af1e8445
Author: Morten Welinder <terra gnome org>
Date:   Sun May 20 13:28:26 2018 -0400

    Derivatives: fix debug output.

 src/expr-deriv.c |   14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/src/expr-deriv.c b/src/expr-deriv.c
index 6654a47..1cbb59c 100644
--- a/src/expr-deriv.c
+++ b/src/expr-deriv.c
@@ -366,8 +366,8 @@ optimize_sum (GnmExpr const *e)
                all_neg = all_neg && is_neg (a);
 
                all_lcmul = all_lcmul &&
-                       is_lcmul (a, &x) &&
-                       ((i == 0) ? ((cl = x), TRUE) : (cl == x));
+                       is_lcmul (a, i ? &x : &cl) &&
+                       (i == 0 || cl == x);
        }
 
        if (all_neg) {
@@ -430,8 +430,8 @@ cb_arg_collect (GnmCellIter const *iter, gpointer user_)
                          cell->pos.col, cell->pos.row,
                          FALSE);
        parse_pos_init_evalpos (&pp, user->ep);
-       // gnm_cellref_set_col_ar (&cr, &pp, user->cr0->col_relative);
-       // gnm_cellref_set_row_ar (&cr, &pp, user->cr0->row_relative);
+       gnm_cellref_set_col_ar (&cr, &pp, user->cr0->col_relative);
+       gnm_cellref_set_row_ar (&cr, &pp, user->cr0->row_relative);
        user->args = gnm_expr_list_prepend
                (user->args,
                 (gpointer)gnm_expr_new_cellref (&cr));
@@ -703,15 +703,17 @@ gnm_expr_top_deriv (GnmExprTop const *texpr,
 
        expr = gnm_expr_deriv (texpr->expr, ep, info);
        if (gnm_debug_flag ("deriv")) {
-               GnmParsePos pp;
+               GnmParsePos pp, ppvar;
                char *s;
                Sheet *sheet = ep->sheet;
                GnmConventions const *convs = sheet_get_conventions (sheet);
 
+               parse_pos_init_evalpos (&ppvar, &info->var);
                parse_pos_init_evalpos (&pp, ep);
+
                s = gnm_expr_top_as_string (texpr, &pp, convs);
                g_printerr ("Derivative of %s with respect to %s:%s",
-                           s, parsepos_as_string (&pp),
+                           s, parsepos_as_string (&ppvar),
                            expr ? "\n" : " cannot compute.\n");
                g_free (s);
                if (expr) {