Support ~USER for some names on MS-Windows

* src/w32.c (getpwnam): Support usernames provided through
LOGNAME or USERNAME environment variables, to mimic what
editfns.c:init_editfns does.

1 files changed, 23 insertions, 1 deletions

diff --git a/src/w32.c b/src/w32.c
index c75a4f918d3..197f6ddee2f 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -2091,7 +2091,29 @@ getpwnam (char *name)
     return pw;
 
   if (xstrcasecmp (name, pw->pw_name))
-    return NULL;
+    {
+      /* Mimic what init_editfns does with these environment
+         variables, so that the likes of ~USER is recognized by
+         expand-file-name even if $LOGNAME gives a name different from
+         the real username produced by the process token.  */
+      char *logname = getenv ("LOGNAME");
+      char *username = getenv ("USERNAME");
+      if ((logname || username)
+          && xstrcasecmp (name, logname ? logname : username) == 0)
+        {
+          static struct passwd alias_user;
+          static char alias_name[PASSWD_FIELD_SIZE];
+
+          memcpy (&alias_user, &dflt_passwd, sizeof dflt_passwd);
+          alias_name[0] = '\0';
+          strncat (alias_name, logname ? logname : username,
+                   PASSWD_FIELD_SIZE - 1);
+          alias_user.pw_name = alias_name;
+          pw = &alias_user;
+        }
+      else
+        return NULL;
+    }
 
   return pw;
 }