do not infloop on a query ending in %XY, for invalid hex X or Y

When a query ends in say %gg, (or any invalid hex) e.g.,
http://git.gnome.org/browse/gdlmm/commit/?id=%gg
convert_query_hexchar calls memmove(txt, txt+3, 0), and then returns
txt-1, so the loop in http_parse_querystring never terminates.  The
solution is to make the memmove also copy the trailing NUL.
* html.c (convert_query_hexchar): Fix off-by-one error.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/html.c b/html.c
index d86b2c1..5336596 100644
--- a/html.c
+++ b/html.c
@@ -156,137 +156,137 @@ void html_url_arg(char *txt)
                         write(htmlfd, fmt("%%%2x", c), 3);
                         txt = t+1;
                 }
                 t++;
         }
         if (t!=txt)
                 html(txt);
 }
 
 void html_hidden(char *name, char *value)
 {
         html("<input type='hidden' name='");
         html_attr(name);
         html("' value='");
         html_attr(value);
         html("'/>");
 }
 
 void html_option(char *value, char *text, 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(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' : '-'));
 }
 
 int html_include(const char *filename)
 {
         FILE *f;
         char buf[4096];
         size_t len;
 
         if (!(f = fopen(filename, "r"))) {
                 fprintf(stderr, "[cgit] Failed to include file %s: %s (%d).\n",
                         filename, strerror(errno), errno);
                 return -1;
         }
         while((len = fread(buf, 1, 4096, f)) > 0)
                 write(htmlfd, buf, len);
         fclose(f);
         return 0;
 }
 
 int hextoint(char c)
 {
         if (c >= 'a' && c <= 'f')
                 return 10 + c - 'a';
         else if (c >= 'A' && c <= 'F')
                 return 10 + c - 'A';
         else if (c >= '0' && c <= '9')
                 return c - '0';
         else
                 return -1;
 }
 
 char *convert_query_hexchar(char *txt)
 {
         int d1, d2, n;
         n = strlen(txt);
         if (n < 3) {
                 *txt = '\0';
                 return txt-1;
         }
         d1 = hextoint(*(txt+1));
         d2 = hextoint(*(txt+2));
         if (d1<0 || d2<0) {
-                memmove(txt, txt+3, n-3);
+                memmove(txt, txt+3, n-2);
                 return txt-1;
         } else {
                 *txt = d1 * 16 + d2;
                 memmove(txt+1, txt+3, n-2);
                 return txt;
         }
 }
 
 int http_parse_querystring(char *txt, void (*fn)(const char *name, const char *value))
 {
         char *t, *value = NULL, c;
 
         if (!txt)
                 return 0;
 
         t = txt = strdup(txt);
         if (t == NULL) {
                 printf("Out of memory\n");
                 exit(1);
         }
         while((c=*t) != '\0') {
                 if (c=='=') {
                         *t = '\0';
                         value = t+1;
                 } else if (c=='+') {
                         *t = ' ';
                 } else if (c=='%') {
                         t = convert_query_hexchar(t);
                 } else if (c=='&') {
                         *t = '\0';
                         (*fn)(txt, value);
                         txt = t+1;
                         value = NULL;
                 }
                 t++;
         }
         if (t!=txt)
                 (*fn)(txt, value);
         return 0;
 }