[gnumeric] ValueArea: fix problems with inverted ranges.

[Morten Welinder <mortenw src gnome org>]

commit e8b6151c027e35d1497172e07e39e63875989899
Author: Morten Welinder <terra gnome org>
Date:   Sun Apr 24 16:07:07 2016 -0400

    ValueArea: fix problems with inverted ranges.
    
    Notably fix problems with ranges that are inverted because a relative
    range went off the edge of the sheet.

 ChangeLog         |    8 ++++++-
 NEWS              |    1 +
 src/value-sheet.c |   58 +++++++++++-----------------------------------------
 3 files changed, 21 insertions(+), 46 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index a5370fa..da55b01 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,12 @@
+2016-04-24  Morten Welinder  <terra gnome org>
+
+       * src/value-sheet.c (value_area_get_x_y): Use
+       gnm_rangeref_normalize.  Do full wrap-around.
+
 2016-04-24  Jean Brefort  <jean brefort normalesup org>
 
-       * src/graph.c (gnm_go_data_matrix_load_values): fix array reading. [#765483]
+       * src/graph.c (gnm_go_data_matrix_load_values): fix array
+       reading. [#765483]
 
 2016-04-17  Jean Brefort  <jean brefort normalesup org>
 
diff --git a/NEWS b/NEWS
index b448636..f907194 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@ Morten:
        * Documentation fixes for complex numbers.
        * Fix rare RANDBETWEEN problem.
        * Test suite improvements.
+       * Fix value-area problem.  [#765438]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.28
diff --git a/src/value-sheet.c b/src/value-sheet.c
index dc179f0..474f2ad 100644
--- a/src/value-sheet.c
+++ b/src/value-sheet.c
@@ -164,58 +164,26 @@ value_area_get_x_y (GnmValue const *v, int x, int y, GnmEvalPos const *ep)
                                      NULL);
                return v->v_array.vals [x][y];
        } else if (VALUE_IS_CELLRANGE (v)) {
-               GnmCellRef const * const a = &v->v_range.cell.a;
-               GnmCellRef const * const b = &v->v_range.cell.b;
-               int a_col = a->col;
-               int a_row = a->row;
-               int b_col = b->col;
-               int b_row = b->row;
+               GnmRange r;
+               Sheet *start_sheet, *end_sheet;
                GnmCell *cell;
-               Sheet *sheet;
-
-               /* Handle relative references */
-               if (a->col_relative)
-                       a_col += ep->eval.col;
-               if (a->row_relative)
-                       a_row += ep->eval.row;
-               if (b->col_relative)
-                       b_col += ep->eval.col;
-               if (b->row_relative)
-                       b_row += ep->eval.row;
-
-               /* Handle inverted references */
-               if (a_row > b_row) {
-                       int tmp = a_row;
-                       a_row = b_row;
-                       b_row = tmp;
-               }
-               if (a_col > b_col) {
-                       int tmp = a_col;
-                       a_col = b_col;
-                       b_col = tmp;
-               }
-
-               a_col += x;
-               a_row += y;
-
-               /*
-                * FIXME FIXME FIXME
-                * This should return NA but some of the math functions may
-                * rely on this for now.
-                */
-               g_return_val_if_fail (a_row<=b_row, NULL);
-               g_return_val_if_fail (a_col<=b_col, NULL);
 
-               sheet = eval_sheet (a->sheet, ep->sheet);
+               gnm_rangeref_normalize (&v->v_range.cell, ep,
+                                       &start_sheet, &end_sheet,
+                                       &r);
+               if (start_sheet != end_sheet)
+                       return NULL;
 
-               g_return_val_if_fail (IS_SHEET (sheet), NULL);
+               // Full wrap-around
+               x = (r.start.col + x) % gnm_sheet_get_max_cols (start_sheet);
+               y = (r.start.row + y) % gnm_sheet_get_max_rows (start_sheet);
 
                /* Speedup */
-               if (sheet->cols.max_used < a_col ||
-                   sheet->rows.max_used < a_row)
+               if (start_sheet->cols.max_used < x ||
+                   start_sheet->rows.max_used < y)
                        return value_new_empty ();
 
-               cell = sheet_cell_get (sheet, a_col, a_row);
+               cell = sheet_cell_get (start_sheet, x, y);
                if (cell != NULL) {
                        gnm_cell_eval (cell);
                        return cell->value;