Properly escape ampersands inside HTML attributes

Ampersands ("&") appearing inside HTML attributes need to be translated
to "&". Otherwise, invalid XHTML will be generated at various
places, such as at tree views containing links to submodules.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/html.c b/html.c
index a0f6db4..24a03a5 100644
--- a/html.c
+++ b/html.c
@@ -45,202 +45,204 @@ char *fmt(const char *format, ...)
 {
 	static char buf[8][1024];
 	static int bufidx;
 	int len;
 	va_list args;
 
 	bufidx++;
 	bufidx &= 7;
 
 	va_start(args, format);
 	len = vsnprintf(buf[bufidx], sizeof(buf[bufidx]), format, args);
 	va_end(args);
 	if (len>sizeof(buf[bufidx])) {
 		fprintf(stderr, "[html.c] string truncated: %s\n", format);
 		exit(1);
 	}
 	return buf[bufidx];
 }
 
 void html_raw(const char *data, size_t size)
 {
 	write(htmlfd, data, size);
 }
 
 void html(const char *txt)
 {
 	write(htmlfd, txt, strlen(txt));
 }
 
 void htmlf(const char *format, ...)
 {
 	static char buf[65536];
 	va_list args;
 
 	va_start(args, format);
 	vsnprintf(buf, sizeof(buf), format, args);
 	va_end(args);
 	html(buf);
 }
 
 void html_status(int code, const char *msg, int more_headers)
 {
 	htmlf("Status: %d %s\n", code, msg);
 	if (!more_headers)
 		html("\n");
 }
 
 void html_txt(const char *txt)
 {
 	const char *t = txt;
 	while(t && *t){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			html_raw(txt, t - txt);
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='&')
 				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_ntxt(int len, const char *txt)
 {
 	const char *t = txt;
 	while(t && *t && len--){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			html_raw(txt, t - txt);
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='&')
 				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html_raw(txt, t - txt);
 	if (len<0)
 		html("...");
 }
 
 void html_attr(const char *txt)
 {
 	const char *t = txt;
 	while(t && *t){
 		int c = *t;
-		if (c=='<' || c=='>' || c=='\'' || c=='\"') {
+		if (c=='<' || c=='>' || c=='\'' || c=='\"' || c=='&') {
 			html_raw(txt, t - txt);
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='\'')
 				html("&#x27;");
 			else if (c=='"')
 				html("&quot;");
+			else if (c=='&')
+				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_url_path(const char *txt)
 {
 	const char *t = txt;
 	while(t && *t){
 		int c = *t;
 		const char *e = url_escape_table[c];
 		if (e && c!='+' && c!='&') {
 			html_raw(txt, t - txt);
 			html(e);
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_url_arg(const char *txt)
 {
 	const char *t = txt;
 	while(t && *t){
 		int c = *t;
 		const char *e = url_escape_table[c];
 		if (c == ' ')
 			e = "+";
 		if (e) {
 			html_raw(txt, t - txt);
 			html(e);
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_hidden(const char *name, const char *value)
 {
 	html("<input type='hidden' name='");
 	html_attr(name);
 	html("' value='");
 	html_attr(value);
 	html("'/>");
 }
 
 void html_option(const char *value, const char *text, const char *selected_value)
 {
 	html("<option value='");
 	html_attr(value);
 	html("'");
 	if (selected_value && !strcmp(selected_value, value))
 		html(" selected='selected'");
 	html(">");
 	html_txt(text);
 	html("</option>\n");
 }
 
 void html_link_open(const char *url, const char *title, const char *class)
 {
 	html("<a href='");
 	html_attr(url);
 	if (title) {
 		html("' title='");
 		html_attr(title);
 	}
 	if (class) {
 		html("' class='");
 		html_attr(class);
 	}
 	html("'>");
 }
 
 void html_link_close(void)
 {
 	html("</a>");
 }
 
 void html_fileperm(unsigned short mode)
 {
 	htmlf("%c%c%c", (mode & 4 ? 'r' : '-'),
 	      (mode & 2 ? 'w' : '-'), (mode & 1 ? 'x' : '-'));
 }
 
 int html_include(const char *filename)
 {
 	FILE *f;
 	char buf[4096];
 	size_t len;