html.c: avoid out-of-bounds access for url_escape_table

This fixes a segfault for me with with -O2 optimization on x86
with gcc (Debian 4.4.5-8) 4.4.5

I can reliably reproduce it with the following parameters
when pointed to the git.git repository:

PATH_INFO='/git-core.git/diff/'
QUERY_STRING='id=2b93bfac0f5bcabbf60f174f4e7bfa9e318e64d5&id2=d6da71a9d16b8cf27f9d8f90692d3625c849cbc8'

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/html.c b/html.c
index 24a03a5..5b07aa0 100644
--- a/html.c
+++ b/html.c
@@ -117,114 +117,114 @@ void html_ntxt(int len, const char *txt)
 		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=='\"' || 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;
+		unsigned char 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;
+		unsigned char 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("'>");