From: Ralph Corderoy <ralph@inputplus.co.uk>
Date: Thu, 7 Sep 2017 09:16:36 +0000 (+0100)
Subject: getpass.c: Don't fileno(NULL) when fopen("/dev/tty") fails.
X-Git-Url: https://diplodocus.org/git/nmh/commitdiff_plain/da05b66b6d580781850f10122f720b8771a739f7?hp=ed4e21fb32d214ed9c45d0bd4eac9d3dd8ee6c9d

getpass.c: Don't fileno(NULL) when fopen("/dev/tty") fails.

If stdin is a TTY, but opening it for writing fails, then stdin and
stderr are used as defaults and the TTY doesn't have echo disabled.  The
later test to restore echo just checks if stdin is a TTY and not that it
was opened successfully causing a NULL FILE pointer to be fileno(3)'d.
Fixes da6af9633.  This function's logic remains a bit contorted;  I went
for the minimal fix.
---

diff --git a/sbr/getpass.c b/sbr/getpass.c
index 4b24af3c..12805f2f 100644
--- a/sbr/getpass.c
+++ b/sbr/getpass.c
@@ -78,7 +78,7 @@ nmh_getpass(const char *prompt)
     *p++ = ch;
   *p = '\0';
 
-  if (istty) {
+  if (istty && fin != stdin) {
     (void)tcsetattr(fileno(fin), TCSANOW, &oterm);
     rewind(fout);
     (void)fputc('\n', fout);