[file-roller] fr-command-rar: check for NULL in name_field

[Paolo Bacchilega <paobac src gnome org>]

commit 8c55a4118dc83f171ca89407492269ecfe0a20d3
Author: Igor Gnatenko <i gnatenko brain gmail com>
Date:   Fri Aug 29 15:19:21 2014 +0600

    fr-command-rar: check for NULL in name_field
    
    When I tried to open rar archive from floppy disk (floppy corrupted), I
    got crash.
    149         if (*name_field == '/') {
    (gdb) p name_field
    $3 = 0x0
    Sure, it can't be dereferenced.
    
    Reference: https://bugzilla.redhat.com/show_bug.cgi?id=1135409
    Reference: https://bugzilla.gnome.org/show_bug.cgi?id=735657
    Signed-off-by: Igor Gnatenko <i gnatenko brain gmail com>

 src/fr-command-rar.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/fr-command-rar.c b/src/fr-command-rar.c
index 7619225..06951c5 100644
--- a/src/fr-command-rar.c
+++ b/src/fr-command-rar.c
@@ -146,6 +146,9 @@ parse_name_field (char         *line,
        else
                name_field = g_strdup (line + 1);
 
+       if (name_field == NULL)
+               return NULL;
+
        if (*name_field == '/') {
                fdata->full_path = g_strdup (name_field);
                fdata->original_path = fdata->full_path;