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
@@ -16,143 +16,142 @@ char *fmt(const char *format, ...)
         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);
 }
-