[master] c4d7754 Correctly quote backslash, even if it is the only thing that needs quoting in the string.

[Poul-Henning Kamp]

commit c4d7754730928c8fe66a206958de5a7b40b9a9ff
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Mon May 16 13:20:58 2011 +0000

    Correctly quote backslash, even if it is the only thing that needs
    quoting in the string.
    
    Fixes	#900

diff --git a/lib/libvarnish/vsb.c b/lib/libvarnish/vsb.c
index d3f044d..ac0c608 100644
--- a/lib/libvarnish/vsb.c
+++ b/lib/libvarnish/vsb.c
@@ -534,7 +534,7 @@ vsb_quote(struct vsb *s, const char *p, int len, int how)
 		len = strlen(p);
 
 	for (q = p; q < p + len; q++) {
-		if (!isgraph(*q) || *q == '"') {
+		if (!isgraph(*q) || *q == '"' || *q == '\\') {
 			quote++;
 			break;
 		}