krb5 commit [krb5-1.15]: Always set appdefault_get() output argument

https://github.com/krb5/krb5/commit/8420b1404f01bdfe85450d569d89c80ac499dabb
commit 8420b1404f01bdfe85450d569d89c80ac499dabb
Author: Nehal J Wani <[email protected]>
Date:   Sun Jan 28 03:02:57 2018 -0500

    Always set appdefault_get() output argument
    
    gcc 7 cannot determine that appdefault_get() always sets *ret_value
    when it returns zero, so issues a "may be used uninitialized" warning
    in its caller.  Set *ret_value at the beginning of the function body
    in accordance with current practices.
    
    [[email protected]: clarified commit message]
    
    (cherry picked from commit 364c608911af2f227695bb527d4e42f091ee8bd3)
    
    ticket: 8639
    version_fixed: 1.15.3

 src/lib/krb5/krb/appdefault.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/src/lib/krb5/krb/appdefault.c b/src/lib/krb5/krb/appdefault.c
index 73fd260..3f7dc23 100644
--- a/src/lib/krb5/krb/appdefault.c
+++ b/src/lib/krb5/krb/appdefault.c
@@ -44,6 +44,8 @@ appdefault_get(krb5_context context, const char *appname, const krb5_data *realm
     krb5_error_code retval;
     const char * realmstr =  realm?realm->data:NULL;
 
+    *ret_value = NULL;
+
     if (!context || (context->magic != KV5M_CONTEXT))
         return KV5M_CONTEXT;