From 8243e43f9f11b8eaae04f371fcb4981cd5450e7f Mon Sep 17 00:00:00 2001
From: Scott Aiton <scott@aiton.net>
Date: Thu, 11 Jan 2024 09:25:07 -0700
Subject: [PATCH] add check

---
 src/patches/clawpatch/fclaw2d_clawpatch_options.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/patches/clawpatch/fclaw2d_clawpatch_options.c b/src/patches/clawpatch/fclaw2d_clawpatch_options.c
index d6dc8d56d..1998f924a 100644
--- a/src/patches/clawpatch/fclaw2d_clawpatch_options.c
+++ b/src/patches/clawpatch/fclaw2d_clawpatch_options.c
@@ -164,6 +164,13 @@ clawpatch_check(fclaw2d_clawpatch_options_t *clawpatch_opt)
         return FCLAW_EXIT_ERROR;            
     }
 
+    if (clawpatch_opt->vtk_patch_threshold < 0)
+    {
+        fclaw_global_essentialf("Clawpatch error : vtk-patch-threshold must be " \
+                                "non-negative.\n");
+        return FCLAW_EXIT_ERROR;            
+    }
+
     return FCLAW_NOEXIT;
 }