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Re: [PATCH] Avoid crippled getpass function on Solaris

From
Jeff King <peff@peff.net>
Date
Aug 7, 2012, 00:35 UTC
Message-ID
<20120807003541.GA18219@sigill.intra.peff.net>
In-Reply-To
<20120807002318.GA17498@sigill.intra.peff.net>
On Mon, Aug 06, 2012 at 08:23:18PM -0400, Jeff King wrote:
> This is all moot if we end up ripping stdio out of this code for other
> reasons, but it does give us another option for a fix.
And here is what that patch would look like:
-- >8 --
Subject: [PATCH] terminal: seek when switching between reading and writing

When a stdio stream is opened in update mode (e.g., "w+"), the C standard forbids switching between reading or writing without an intervening positioning function. Many implementations are lenient about this, but Solaris libc will flush the recently-read contents to the output buffer. In this instance, that meant writing the non-echoed password that the user just typed to the terminal.

Fix it by inserting a no-op fseek between the read and write.

The opposite direction (writing immediately followed by
reading) is also disallowed, but our fflush immediately
after printing the prompt is sufficient to satisfy the
standard.
---
 compat/terminal.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/compat/terminal.c b/compat/terminal.c
index 6d16c8f..bbb038d 100644
--- a/compat/terminal.c
+++ b/compat/terminal.c
@@ -59,6 +59,7 @@ char *git_terminal_prompt(const char *prompt, int echo)
 
 	r = strbuf_getline(&buf, fh, '\n');
 	if (!echo) {
+		fseek(fh, SEEK_CUR, 0);
 		putc('\n', fh);
 		fflush(fh);
 	}
Previous: Jeff KingNext: Tay Ray Chuan
Message 18 of 27 in “Avoid crippled getpass function on Solaris”
  1. Avoid crippled getpass function on SolarisBen Walton, Aug 5, 2012
  2. Tay Ray ChuanAug 6, 2012
  3. Ben WaltonAug 6, 2012
  4. Junio C HamanoAug 6, 2012
  5. Ben WaltonAug 6, 2012
  6. Jeff KingAug 6, 2012
  7. Junio C HamanoAug 6, 2012
  8. Ben WaltonAug 6, 2012
  9. Jeff KingAug 6, 2012
  10. Ben WaltonAug 6, 2012
  11. Jeff KingAug 6, 2012
  12. Ben WaltonAug 6, 2012
  13. Jeff KingAug 6, 2012
  14. Ben WaltonAug 6, 2012
  15. Jeff KingAug 7, 2012
  16. Andreas SchwabAug 6, 2012
  17. Jeff KingAug 7, 2012
  18. Jeff KingAug 7, 2012
  19. Tay Ray ChuanAug 7, 2012
  20. Ben WaltonAug 7, 2012
  21. Enable HAVE_DEV_TTY for SolarisBen Walton, Aug 7, 2012
  22. Junio C HamanoAug 7, 2012
  23. Jeff KingAug 7, 2012
  24. Jeff KingAug 7, 2012
  25. Ben WaltonAug 7, 2012
  26. Erik Faye-LundAug 8, 2012
  27. Jeff KingAug 8, 2012

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