[gnumeric] Names: plug leak.

[Morten Welinder <mortenw src gnome org>]

commit b593040e29a05bf1de7f0d094029e7ff3f7b593a
Author: Morten Welinder <terra gnome org>
Date:   Sat Feb 26 12:31:53 2022 -0500

    Names: plug leak.
    
    Hard-to-hit leak relating to shared expressions.

 ChangeLog       | 4 ++++
 NEWS            | 1 +
 src/expr-name.c | 6 +++++-
 3 files changed, 10 insertions(+), 1 deletion(-)
---
diff --git a/ChangeLog b/ChangeLog
index c557eea0d..7f7932cdd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2022-02-26  Morten Welinder  <terra gnome org>
+
+       * src/expr-name.c (expr_name_set_expr): Plug leak.
+
 2022-01-21  Morten Welinder  <terra gnome org>
 
        * src/wbc-gtk-actions.c: In vertical toolbar mode, show a combo
diff --git a/NEWS b/NEWS
index 31058c2a3..ee3bbfc1e 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,7 @@ Morten:
        * Fix BITAND.
        * Test improvements.
        * Fix xlsx write for sheet objects with text contents.  [#617]
+       * Fix leak.
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.51
diff --git a/src/expr-name.c b/src/expr-name.c
index f9d50cd8e..08ff9287d 100644
--- a/src/expr-name.c
+++ b/src/expr-name.c
@@ -1041,8 +1041,12 @@ expr_name_set_expr (GnmNamedExpr *nexpr, GnmExprTop const *texpr)
 
        g_return_if_fail (nexpr != NULL);
 
-       if (texpr == nexpr->texpr)
+       if (texpr == nexpr->texpr) {
+               if (texpr)
+                       gnm_expr_top_unref (texpr);
                return;
+       }
+
        if (nexpr->texpr != NULL) {
                GSList *deps = NULL, *junk = NULL;