[gnumeric] xml: fix problem with circular names

[Morten Welinder <mortenw src gnome org>]

commit 0122da3bd22a936ec6ecd4afb6a536f3961c33b0
Author: Morten Welinder <terra gnome org>
Date:   Tue Jun 16 13:54:42 2015 -0400

    xml: fix problem with circular names

 ChangeLog          |    5 +++++
 NEWS               |    1 +
 src/xml-sax-read.c |   11 ++++++++---
 3 files changed, 14 insertions(+), 3 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 09906c3..c608b98 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-16  Morten Welinder  <terra gnome org>
+
+       * src/xml-sax-read.c (handle_delayed_names): Check for circularity
+       in names.  Fixes #751056.
+
 2015-05-27  Morten Welinder  <terra gnome org>
 
        * src/print.c (compute_scale_fit_to): Attempt a workaround for fp
diff --git a/NEWS b/NEWS
index 755a3fc..d3d90bf 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,7 @@ Morten:
        * Make compilation with clang work again.  [#749138]
        * Fix xlsx problem with import of header/footer.  [#750853]
        * Fix xls save problem with characters outside codepage.  [#750856]
+       * Fix named expression problem.  [#751056]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.22
diff --git a/src/xml-sax-read.c b/src/xml-sax-read.c
index ed4d0a4..b042870 100644
--- a/src/xml-sax-read.c
+++ b/src/xml-sax-read.c
@@ -2932,11 +2932,16 @@ handle_delayed_names (XMLSaxParseState *state)
                                            GNM_EXPR_PARSE_DEFAULT,
                                            state->convs,
                                            &perr);
-               if (texpr) {
+               if (!texpr) {
+                         go_io_warning (state->context, "%s", perr.err->message);
+               } else if (expr_name_check_for_loop (expr_name_name (nexpr), texpr)) {
+                       g_printerr ("Ignoring would-be circular definition of %s\n",
+                                   expr_name_name (nexpr));
+                       gnm_expr_top_unref (texpr);
+               } else {
                        nexpr->pos.eval = pp.eval;
                        expr_name_set_expr (nexpr, texpr);
-               } else
-                       go_io_warning (state->context, "%s", perr.err->message);
+               }
 
                parse_error_free (&perr);
                g_free (expr_str);