[sysprof: 4/63] sysprof-dump: Move error handling up to avoid a NULL pointer dereference

[Christian Hergert <chergert src gnome org>]

commit 3eb0f3e964177e20452f98ddff965aac91f0dc82
Author: Philip Withnall <withnall endlessm com>
Date:   Tue Jun 30 16:21:38 2020 +0100

    sysprof-dump: Move error handling up to avoid a NULL pointer dereference
    
    `reader` can be `NULL`, but the `NULL` check was done after potentially
    dereferencing it.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    Helps: #40

 src/tools/sysprof-dump.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
---
diff --git a/src/tools/sysprof-dump.c b/src/tools/sysprof-dump.c
index 8b99624..2439490 100644
--- a/src/tools/sysprof-dump.c
+++ b/src/tools/sysprof-dump.c
@@ -56,7 +56,11 @@ main (gint argc,
       return EXIT_FAILURE;
     }
 
-  reader = sysprof_capture_reader_new (argv[1], &error);
+  if ((reader = sysprof_capture_reader_new (argv[1], &error)) == NULL)
+    {
+      g_printerr ("%s\n", error->message);
+      return EXIT_FAILURE;
+    }
 
   if (list_files)
     {
@@ -75,12 +79,6 @@ main (gint argc,
 #define SET_CTR_TYPE(i,t) g_hash_table_insert(ctrtypes, GINT_TO_POINTER(i), GINT_TO_POINTER(t))
 #define GET_CTR_TYPE(i) GPOINTER_TO_INT(g_hash_table_lookup(ctrtypes, GINT_TO_POINTER(i)))
 
-  if (reader == NULL)
-    {
-      g_printerr ("%s\n", error->message);
-      return EXIT_FAILURE;
-    }
-
   begin_time = sysprof_capture_reader_get_start_time (reader);
   end_time = sysprof_capture_reader_get_end_time (reader);