html: fix strcpy bug in convert_query_hexchar

The source and destination strings in strcpy() may not overlap.
Instead, use memmove(), which allows overlap.  This fixes test t0104,
where 'url=foo%2bbar/tree' was being parsed improperly.

Signed-off-by: Mark Lodato <lodatom@gmail.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/html.c b/html.c
index 66ba65d..d86b2c1 100644
--- a/html.c
+++ b/html.c
@@ -240,19 +240,20 @@ int hextoint(char c)
 
 char *convert_query_hexchar(char *txt)
 {
-        int d1, d2;
-        if (strlen(txt) < 3) {
+        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) {
-                strcpy(txt, txt+3);
+                memmove(txt, txt+3, n-3);
                 return txt-1;
         } else {
                 *txt = d1 * 16 + d2;
-                strcpy(txt+1, txt+3);
+                memmove(txt+1, txt+3, n-2);
                 return txt;
         }
 }