Escape &<> when they appear in href text.

[originally from svn r8743]

2 files changed, 20 insertions, 2 deletions

diff --git a/bk_html.c b/bk_html.c
index 90800f1..e3202a5 100644
--- a/bk_html.c
+++ b/bk_html.c
@@ -2176,7 +2176,7 @@ static void html_words(htmloutput *ho, word *words, int flags,
 		       htmlfile *file, keywordlist *keywords, htmlconfig *cfg)
 {
     word *w;
-    char *c;
+    char *c, *c2, *p, *q;
     int style, type;
 
     for (w = words; w; w = w->next) switch (w->type) {
@@ -2184,7 +2184,20 @@ static void html_words(htmloutput *ho, word *words, int flags,
 	if (flags & LINKS) {
 	    element_open(ho, "a");
 	    c = utoa_dup(w->text, CS_ASCII);
-	    element_attr(ho, "href", c);
+	    c2 = snewn(1 + 10*strlen(c), char);
+	    for (p = c, q = c2; *p; p++) {
+		if (*p == '&')
+		    q += sprintf(q, "&");
+		else if (*p == '<')
+		    q += sprintf(q, "&lt;");
+		else if (*p == '>')
+		    q += sprintf(q, "&gt;");
+		else
+		    *q++ = *p;
+	    }
+	    *q = '\0';
+	    element_attr(ho, "href", c2);
+	    sfree(c2);
 	    sfree(c);
 	}
 	break;
diff --git a/inputs/test.but b/inputs/test.but
index b1f669a..dddc2dd 100644
--- a/inputs/test.but
+++ b/inputs/test.but
@@ -278,6 +278,11 @@ Similarly, we should support things like hyperlinks
 and \e{in the \W{http://www.tartarus.org/}{middle} of them}, and also
 \e{at the \W{http://home.att.net/~cecw/lastpage.htm}{end}}.
 
+Here's a hyperlink containing some special characters:
+\W{http://a<b&c>d/}{here}. (Not that it'll \e{work}, but you can at
+least determine that it's been correctly escaped by inspection of
+the output HTML.)
+
 \#{FIXME: Unfortunately, we still don't quite do the right thing with
 references:
 How about a \e{reference to \k{subhead} here}? And at