[gnumeric] glpk-solver: fix stopping a runaway solver.

[Morten Welinder <mortenw src gnome org>]

commit 8955972d73ff2fd817cd9fe4b73cb1c7a66b6f3a
Author: Morten Welinder <terra gnome org>
Date:   Wed Jan 10 14:22:31 2018 -0500

    glpk-solver: fix stopping a runaway solver.

 NEWS                    |    1 +
 plugins/glpk/ChangeLog  |    5 +++++
 plugins/glpk/gnm-glpk.c |    2 +-
 3 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/NEWS b/NEWS
index 84e8f4c..0a2781a 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@ Morten:
        * Fix ssdiff problem.  [#792038]
        * Fix ISREF.
        * Some internal array formula code cleanups.
+       * Fix problem with stopping a glpk solver.
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.38
diff --git a/plugins/glpk/ChangeLog b/plugins/glpk/ChangeLog
index 161bb75..236a49c 100644
--- a/plugins/glpk/ChangeLog
+++ b/plugins/glpk/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-10  Morten Welinder  <terra gnome org>
+
+       * gnm-glpk.c (gnm_glpk_stop): Fix precondition preventing the
+       stopping of a runaway solver.
+
 2017-12-28  Morten Welinder <terra gnome org>
 
        * Release 1.12.38
diff --git a/plugins/glpk/gnm-glpk.c b/plugins/glpk/gnm-glpk.c
index c85c86d..32326e6 100644
--- a/plugins/glpk/gnm-glpk.c
+++ b/plugins/glpk/gnm-glpk.c
@@ -612,7 +612,7 @@ gnm_glpk_start (GnmSolver *sol, WorkbookControl *wbc, GError **err,
 static gboolean
 gnm_glpk_stop (GnmSolver *sol, GError *err, GnmGlpk *lp)
 {
-       g_return_val_if_fail (sol->status != GNM_SOLVER_STATUS_RUNNING, FALSE);
+       g_return_val_if_fail (sol->status == GNM_SOLVER_STATUS_RUNNING, FALSE);
 
        gnm_glpk_cleanup (lp);