[gnome-builder] plugins: be more careful about priority overflow

[Christian Hergert <chergert src gnome org>]

commit 16e71e9fb8743dc3456801e84976e8ada18261c3
Author: Christian Hergert <chergert redhat com>
Date:   Mon May 13 13:38:54 2019 -0700

    plugins: be more careful about priority overflow

 src/libide/gui/ide-workbench.c                 | 7 ++++++-
 src/libide/plugins/ide-extension-set-adapter.c | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/src/libide/gui/ide-workbench.c b/src/libide/gui/ide-workbench.c
index 35aa809f2..532e81015 100644
--- a/src/libide/gui/ide-workbench.c
+++ b/src/libide/gui/ide-workbench.c
@@ -1872,7 +1872,12 @@ sort_by_priority (gconstpointer a,
   if (!ide_workbench_addin_can_open (addin_b, o->file, o->content_type, &prio_b))
     return -1;
 
-  return prio_a - prio_b;
+  if (prio_a < prio_b)
+    return -1;
+  else if (prio_a > prio_b)
+    return 1;
+  else
+    return 0;
 }
 
 static void
diff --git a/src/libide/plugins/ide-extension-set-adapter.c b/src/libide/plugins/ide-extension-set-adapter.c
index d4586b1f6..77a54a9f1 100644
--- a/src/libide/plugins/ide-extension-set-adapter.c
+++ b/src/libide/plugins/ide-extension-set-adapter.c
@@ -678,7 +678,12 @@ sort_by_priority (gconstpointer a,
 
   /* Greater values are higher priority */
 
-  return sb->priority - sa->priority;
+  if (sa->priority < sb->priority)
+    return -1;
+  else if (sa->priority > sb->priority)
+    return 1;
+  else
+    return 0;
 }
 
 /**