[gnumeric] xls: Fix duplicate sheet problem differently.

[Morten Welinder <mortenw src gnome org>]

commit 92427cd94335ff5959e57fb7aaa28007237be852
Author: Morten Welinder <terra gnome org>
Date:   Mon Jan 4 16:44:40 2016 -0500

    xls: Fix duplicate sheet problem differently.

 plugins/excel/ChangeLog       |    3 ++
 plugins/excel/ms-excel-read.c |   48 ++++++++++++++++++++++++----------------
 2 files changed, 32 insertions(+), 19 deletions(-)
---
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index 2859d86..87fdd80 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,5 +1,8 @@
 2016-01-04  Morten Welinder  <terra gnome org>
 
+       * ms-excel-read.c (excel_sheet_new): Undo last change.  Fix
+       #760103 differently.
+
        * ms-obj.c (ms_obj_read_biff8_obj): Fuzzed file fixes.  Fixes
        #760101 and #760105.
 
diff --git a/plugins/excel/ms-excel-read.c b/plugins/excel/ms-excel-read.c
index a8bf7bc..5f9a253 100644
--- a/plugins/excel/ms-excel-read.c
+++ b/plugins/excel/ms-excel-read.c
@@ -885,34 +885,44 @@ excel_sheet_new (GnmXLImporter *importer, char const *sheet_name, GnmSheetType t
                &ms_sheet_get_fmt,
                NULL
        };
-
-       ExcelReadSheet *esheet = g_new (ExcelReadSheet, 1);
+       int rows = (importer->ver >= MS_BIFF_V8 ? XLS_MaxRow_V8 : XLS_MaxRow_V7);
+       ExcelReadSheet *esheet;
        Sheet *sheet;
-       char *real_name;
-
-       real_name = workbook_sheet_get_free_name (importer->wb, sheet_name, FALSE, TRUE);
-       sheet = sheet_new_with_type (importer->wb, real_name, type,
-                                    XLS_MaxCol,
-                                    (importer->ver >= MS_BIFF_V8
-                                     ? XLS_MaxRow_V8
-                                     : XLS_MaxRow_V7));
-       workbook_sheet_attach (importer->wb, sheet);
-       d (1, g_printerr ("Adding sheet '%s'\n", real_name););
-       g_free (real_name);
+
+       sheet = workbook_sheet_by_name (importer->wb, sheet_name);
+       if (sheet) {
+               unsigned ui;
+
+               for (ui = 0; ui < importer->excel_sheets->len; ui++) {
+                       ExcelReadSheet *es = g_ptr_array_index (importer->excel_sheets, ui);
+                       if (es->sheet == sheet) {
+                               g_warning ("Duplicate definition of sheet %s\n", sheet_name);
+                               return NULL;
+                       }
+               }
+       } else {
+               sheet = sheet_new_with_type (importer->wb, sheet_name, type,
+                                            XLS_MaxCol, rows);
+               workbook_sheet_attach (importer->wb, sheet);
+               d (1, g_printerr ("Adding sheet '%s'\n", sheet_name););
+       }
 
        /* Flag a respan here in case nothing else does */
        sheet_flag_recompute_spans (sheet);
 
+       esheet = g_new (ExcelReadSheet, 1);
        esheet->sheet   = sheet;
        esheet->filter  = NULL;
        esheet->freeze_panes = FALSE;
        esheet->active_pane  = 3; /* The default */
-       esheet->shared_formulae = g_hash_table_new_full (
-                                                        (GHashFunc)&gnm_cellpos_hash, 
(GCompareFunc)&gnm_cellpos_equal,
-                                                        NULL, (GDestroyNotify) &excel_shared_formula_free);
-       esheet->tables          = g_hash_table_new_full (
-                                                        (GHashFunc)&gnm_cellpos_hash, 
(GCompareFunc)&gnm_cellpos_equal,
-                                                        NULL, (GDestroyNotify) g_free);
+       esheet->shared_formulae = g_hash_table_new_full
+               ((GHashFunc)&gnm_cellpos_hash,
+                (GCompareFunc)&gnm_cellpos_equal,
+                NULL, (GDestroyNotify) &excel_shared_formula_free);
+       esheet->tables = g_hash_table_new_full
+               ((GHashFunc)&gnm_cellpos_hash,
+                (GCompareFunc)&gnm_cellpos_equal,
+                NULL, (GDestroyNotify) g_free);
        esheet->biff2_prev_xf_index = -1;
 
        excel_init_margins (esheet);