krb5 commit [krb5-1.21]: Fix krb5_cccol_have_content() bad pointer free

https://github.com/krb5/krb5/commit/bdfb45dd88fe222df03086158b1b52c5056847a5
commit bdfb45dd88fe222df03086158b1b52c5056847a5
Author: Ilya Gladyshev <[email protected]>
Date:   Wed Aug 30 21:19:59 2023 +0100

    Fix krb5_cccol_have_content() bad pointer free
    
    krb5_cccol_have_content() calls krb5_cc_get_principal() within a loop,
    and frees the resulting principal on success or failure.  Set princ to
    null before each call to ensure we don't free a dangling pointer.
    
    [[email protected]: rewrote commit message; moved assignment for greater
    clarity]
    
    (cherry picked from commit 635c8cca65b745476d07c1f5ff701445db25c10d)
    
    ticket: 9103
    version_fixed: 1.21.3

 src/lib/krb5/ccache/cccursor.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/lib/krb5/ccache/cccursor.c b/src/lib/krb5/ccache/cccursor.c
index 4bcb66b71..926873f2a 100644
--- a/src/lib/krb5/ccache/cccursor.c
+++ b/src/lib/krb5/ccache/cccursor.c
@@ -249,6 +249,7 @@ krb5_cccol_have_content(krb5_context context)
         save_first_error(context, ret, &errsave);
         if (ret || cache == NULL)
             break;
+        princ = NULL;
         ret = krb5_cc_get_principal(context, cache, &princ);
         save_first_error(context, ret, &errsave);
         if (!ret)