[PATCH] q-value calculation for 'Accept:'ed content-types produces wrong values

[Kai Tetzlaff]

I've been using the WAP GW with a mobile which appends q-values to it's 
'Accept:' headers in its WSP Connect meassage. I noticed that Kannel's 
decoded q-value differs from the one the mobile sends. So far, this 
would be a minor problem but in some cases, if the decoded q-value is 
above 1000, Kannel stops to extract further Accept headers. This may 
then lead to HTTP/WSP '406 Not acceptable' being forwarded to the mobile 
(instead of the real HTTP response) beacuse Kannel does not have the 
correct list of acceptable content-types.

I already filed a bug (#198) in Kannel/Mantis but it looks like this 
list is the better place ...

I've attached a patch against wsp_headers.c which solves this issue (and 
another one which is closely related).

Cheers,
Kai
Index: wap/wsp_headers.c
===================================================================
RCS file: /home/cvs/gateway/wap/wsp_headers.c,v
retrieving revision 1.22
diff -u -p -d -r1.22 wsp_headers.c
--- wap/wsp_headers.c   11 Feb 2005 15:59:18 -0000      1.22
+++ wap/wsp_headers.c   3 Mar 2005 22:21:21 -0000
@@ -251,8 +251,9 @@ static Octstr *convert_q_value(int q)
     }
     /* Three decimal quality factors shall be multiplied with 1000
-     * and incremented by 100. */
-    if (q > 100 && q <= 1000) {
+     * and incremented by 100. I.e. the values to be converted range from
+     * 101 (.001 * 1000 + 100) to 1099 (.999 * 1000 + 100). */
+    if (q > 100 && q < 1100) {
         q = q - 100;
         result = octstr_create("0.");
         octstr_append_char(result, (q / 100) + '0');
@@ -270,6 +271,9 @@ static Octstr *convert_q_value(int q)
 static Octstr *unpack_q_value(ParseContext *context)
 {
     int c, c2;
+
+    /* better use the existing parse_get_uintvar(..) to extract the
+     * encoded uintvar? */
     c = parse_get_char(context);
     if (c < 0)
@@ -279,7 +283,7 @@ static Octstr *unpack_q_value(ParseConte
         c2 = parse_get_char(context);
         if (c2 < 0 || (c2 & 0x80))
             return NULL;
-        c = ((c & 0x7f) << 8) + c2;
+        c = ((c & 0x7f) << 7) + c2;
     }
     return convert_q_value(c);