Test for NULL-pointers in html_txt() and friends

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/html.c b/html.c
index 957b326..3a5d28d 100644
--- a/html.c
+++ b/html.c
@@ -1,158 +1,157 @@
 /* html.c: helper functions for html output
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 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]))
 		die("[html.c] string truncated: %s", format);
 	return buf[bufidx];
 }
 
 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_txt(char *txt)
 {
 	char *t = txt;
-	while(*t){
+	while(t && *t){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			*t = '\0';
 			html(txt);
 			*t = c;
 			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, char *txt)
 {
 	char *t = txt;
-	while(*t && len--){
+	while(t && *t && len--){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='&') {
 			*t = '\0';
 			html(txt);
 			*t = c;
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='&')
 				html("&amp;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt) {
 		char c = *t;
 		*t = '\0';
 		html(txt);
 		*t = c;
 	}
 	if (len<0)
 		html("...");
 }
 
 void html_attr(char *txt)
 {
 	char *t = txt;
-	while(*t){
+	while(t && *t){
 		int c = *t;
 		if (c=='<' || c=='>' || c=='\'') {
 			*t = '\0';
 			html(txt);
 			*t = c;
 			if (c=='>')
 				html("&gt;");
 			else if (c=='<')
 				html("&lt;");
 			else if (c=='\'')
 				html("&quote;");
 			txt = t+1;
 		}
 		t++;
 	}
 	if (t!=txt)
 		html(txt);
 }
 
 void html_link_open(char *url, char *title, 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' : '-'));
 }
 
 void html_filemode(unsigned short mode)
 {
 	if (S_ISDIR(mode))
 		html("d");
 	else if (S_ISLNK(mode))
 		html("l");
 	else
 		html("-");
 	html_fileperm(mode >> 6);
 	html_fileperm(mode >> 3);
 	html_fileperm(mode);
 }
-