[gnumeric] xls: attempt a fix for corrupted hash table.

[Morten Welinder <mortenw src gnome org>]

commit 65fd6ad6825e1d35eb7baa15fc8f52073efc1e24
Author: Morten Welinder <terra gnome org>
Date:   Fri May 15 11:20:13 2015 -0400

    xls: attempt a fix for corrupted hash table.

 NEWS                          |    1 +
 plugins/excel/ChangeLog       |    5 +++++
 plugins/excel/ms-excel-read.c |   31 +++++++++++++++++--------------
 3 files changed, 23 insertions(+), 14 deletions(-)
---
diff --git a/NEWS b/NEWS
index f8b6b25..c8ca296 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,7 @@ Morten:
        * Fuzzed file fixes.  [#748595] [#748597] [#749031] [#749030]
          [#749069] [#748533] [#749118] [#749166] [#749181] [#749184]
          [#749236] [#749240] [#749234] [#749235] [#749271] [#749270]
+         [#749424]
        * Make solver check linearity of model.
        * Fix xls saving of marker style.  [#749185]
        * Make compilation with clang work again.  [#749138]
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index bf9a73c..eb7ae2f 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,3 +1,8 @@
+2015-05-15  Morten Welinder  <terra gnome org>
+
+       * ms-excel-read.c (excel_formula_shared): Catch duplicate shared
+       formulas for the same cell.
+
 2015-05-14  Morten Welinder  <terra gnome org>
 
        * ms-excel-read.c (excel_read_FILEPASS): Constify.
diff --git a/plugins/excel/ms-excel-read.c b/plugins/excel/ms-excel-read.c
index 5b8cf6d..e9ea731 100644
--- a/plugins/excel/ms-excel-read.c
+++ b/plugins/excel/ms-excel-read.c
@@ -2771,7 +2771,6 @@ excel_formula_shared (BiffQuery *q, ExcelReadSheet *esheet, GnmCell *cell)
        gboolean is_array;
        GnmExprTop const *texpr;
        guint8 const *data;
-       XLSharedFormula *sf;
 
        if (!ms_biff_query_peek_next (q, &opcode) ||
            !(opcode == BIFF_SHRFMLA ||
@@ -2838,22 +2837,26 @@ excel_formula_shared (BiffQuery *q, ExcelReadSheet *esheet, GnmCell *cell)
                                     data, data_len, array_data_len,
                                     !is_array, NULL);
 
-       sf = g_new (XLSharedFormula, 1);
+       if (g_hash_table_lookup (esheet->shared_formulae, &cell->pos)) {
+               g_printerr ("Duplicate shared formula for cell %s\n", cell_name (cell));
+       } else {
+               XLSharedFormula *sf = g_new (XLSharedFormula, 1);
 
-       /* WARNING: Do NOT use the upper left corner as the hashkey.
-        *     For some bizzare reason XL appears to sometimes not
-        *     flag the formula as shared until later.
-        *  Use the location of the cell we are reading as the key.
-        */
-       sf->key = cell->pos;
-       sf->is_array = is_array;
-       sf->data = data_len > 0 ? g_memdup (data, data_len + array_data_len) : NULL;
-       sf->data_len = data_len;
-       sf->array_data_len = array_data_len;
+               /* WARNING: Do NOT use the upper left corner as the hashkey.
+                *     For some bizzare reason XL appears to sometimes not
+                *     flag the formula as shared until later.
+                *  Use the location of the cell we are reading as the key.
+                */
+               sf->key = cell->pos;
+               sf->is_array = is_array;
+               sf->data = data_len > 0 ? g_memdup (data, data_len + array_data_len) : NULL;
+               sf->data_len = data_len;
+               sf->array_data_len = array_data_len;
 
-       d (1, g_printerr ("Shared formula, extent %s\n", range_as_string (&r)););
+               d (1, g_printerr ("Shared formula, extent %s\n", range_as_string (&r)););
 
-       g_hash_table_insert (esheet->shared_formulae, &sf->key, sf);
+               g_hash_table_insert (esheet->shared_formulae, &sf->key, sf);
+       }
 
        g_return_val_if_fail (texpr != NULL, NULL);