From 9a9c016baef51552c27176814849202c05626aaa Mon Sep 17 00:00:00 2001
From: "John \"Elwin\" Edwards" <elwin@rlgallery.org>
Date: Wed, 1 Mar 2017 20:40:18 -0500
Subject: [PATCH] UltraRogue: check the return value from getpwuid().

It is possible for getpwuid() to return NULL.  Such a failure will no
longer cause a segfault.  However, the call to getpwuid() may normally
not be reachable.
---
 urogue/mdport.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/urogue/mdport.c b/urogue/mdport.c
index ae19272..827a6b9 100644
--- a/urogue/mdport.c
+++ b/urogue/mdport.c
@@ -244,7 +244,8 @@ md_getusername(int uid)
 
     pw = getpwuid(getuid());
 
-    l = pw->pw_name;
+    if (pw != NULL)
+        l = pw->pw_name;
 #endif
 
     if ((l == NULL) || (*l == '\0'))
@@ -275,7 +276,8 @@ md_gethomedir()
     struct passwd *pw;
     pw = getpwuid(getuid());
 
-    h = pw->pw_dir;
+    if (pw != NULL)
+        h = pw->pw_dir;
 
     if (strcmp(h,"/") == 0)
         h = NULL;
@@ -335,7 +337,8 @@ md_getshell()
     char *def = "/bin/sh";
     struct passwd *pw;
     pw = getpwuid(getuid());
-    s = pw->pw_shell;
+    if (pw != NULL)
+        s = pw->pw_shell;
 #endif
     if ((s == NULL) || (*s == '\0'))
         if ( (s = getenv("COMSPEC")) == NULL)
@@ -455,13 +458,13 @@ md_getrealname(int uid)
 #if !defined(_WIN32) && !defined(DJGPP)
     struct passwd *pp;
 
-	if ((pp = getpwuid(uid)) == NULL)
+    if ((pp = getpwuid(uid)) == NULL)
     {
         sprintf(uidstr,"%d", uid);
         return(uidstr);
     }
-	else
-	    return(pp->pw_name);
+    else
+        return(pp->pw_name);
 #else
    sprintf(uidstr,"%d", uid);
    return(uidstr);