[PATCH:xdm 5/5] Simplify FailedLogin code

[Alan Coopersmith]

Relies on username going out of scope to discard the pointer returned by
pam_get_item that pam_end frees at the bottom of the loop.

Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
---
 greeter/greet.c |   50 +++++++++++++++++++++++---------------------------
 1 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/greeter/greet.c b/greeter/greet.c
index 8426a65..87d2a83 100644
--- a/greeter/greet.c
+++ b/greeter/greet.c
@@ -402,11 +402,9 @@ Greet (struct display *d, struct greet_info *greet)
 
 
 static void
-FailedLogin (struct display *d, struct greet_info *greet)
+FailedLogin (struct display *d, const char *username)
 {
 #ifdef USE_SYSLOG
-    const char *username = greet->name;
-
     if (username == NULL)
 	username = "username unavailable";
 
@@ -415,10 +413,6 @@ FailedLogin (struct display *d, struct greet_info *greet)
 	   d->name, username);
 #endif
     DrawFail (login);
-#ifndef USE_PAM
-    bzero (greet->name, strlen(greet->name));
-    bzero (greet->password, strlen(greet->password));
-#endif
 }
 
 _X_EXPORT
@@ -500,7 +494,6 @@ greet_user_rtn GreetUser(
 	struct myconv_data pcd		= { d, greet, NULL };
 	struct pam_conv   pc 		= { pamconv, &pcd };
 	const char *	  pam_fname;
-	char *		  username	= NULL;
 	const char *	  login_prompt;
 
 
@@ -586,12 +579,16 @@ greet_user_rtn GreetUser(
 
 	RUN_AND_CHECK_PAM_ERROR(pam_setcred,
 				(*pamhp, 0));
-	RUN_AND_CHECK_PAM_ERROR(pam_get_item,
-				(*pamhp, PAM_USER, (void *) &username));
-	if (username != NULL) {
-	    Debug("PAM_USER: %s\n", username);
-	    greet->name = username;
-	    greet->password = NULL;
+	{
+	    char *username	= NULL;
+
+	    RUN_AND_CHECK_PAM_ERROR(pam_get_item,
+				    (*pamhp, PAM_USER, (void *) &username));
+	    if (username != NULL) {
+		Debug("PAM_USER: %s\n", username);
+		greet->name = username;
+		greet->password = NULL;
+	    }
 	}
 
       pam_done:
@@ -606,19 +603,14 @@ greet_user_rtn GreetUser(
 	    break;
 	} else {
 	    /* Try to fill in username for failed login error log */
-	    if (greet->name == NULL) {
-		if (username == NULL) {
-		    RUN_AND_CHECK_PAM_ERROR(pam_get_item,
-					    (*pamhp, PAM_USER,
-					     (void *) &username));
-		}
-		greet->name = username;
-	    }
-	    FailedLogin (d, greet);
-	    if (greet->name == username) {
-		/* pam_end frees the value returned by pam_get_item */
-		greet->name = NULL;
+	    char *username = greet->name;
+
+	    if (username == NULL) {
+		RUN_AND_CHECK_PAM_ERROR(pam_get_item,
+					(*pamhp, PAM_USER,
+					 (void *) &username));
 	    }
+	    FailedLogin (d, username);
 	    RUN_AND_CHECK_PAM_ERROR(pam_end,
 				    (*pamhp, pam_error));
 	}
@@ -638,7 +630,11 @@ greet_user_rtn GreetUser(
 	if (Verify (d, greet, verify))
 	    break;
 	else
-	    FailedLogin (d, greet);
+	{
+	    FailedLogin (d, greet->name);
+	    bzero (greet->name, strlen(greet->name));
+	    bzero (greet->password, strlen(greet->password));
+	}
 #endif
     }
     DeleteXloginResources (d, *dpy);
-- 
1.7.3.2