cookie: fix memory leak if path was set twice in header

... this will let the second occurance override the first.

Added test 1161 to verify.

Reported-by: Max Dymond
Fixes #1932
Closes #1933

lib/cookie.c

@@ -499,6 +499,7 @@ Curl_cookie_add(struct Curl_easy *data,
             badcookie = TRUE; /* out of memory bad */
             break;
           }
+          free(co->spath); /* if this is set again */
           co->spath = sanitize_cookie_path(co->path);
           if(!co->spath) {
             badcookie = TRUE; /* out of memory bad */

tests/data/Makefile.inc

@@ -123,7 +123,7 @@ test1128 test1129 test1130 test1131 test1132 test1133 test1134 test1135 \
 test1136 test1137 test1138 test1139 test1140 test1141 test1142 test1143 \
 test1144 test1145 test1146 test1147 test1148 test1149 test1150 test1151 \
 \
-test1160 \
+test1160 test1161 \
 test1200 test1201 test1202 test1203 test1204 test1205 test1206 test1207 \
 test1208 test1209 test1210 test1211 test1212 test1213 test1214 test1215 \
 test1216 test1217 test1218 test1219 \

tests/data/test1161

@@ -0,0 +1,54 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+cookies
+</keywords>
+</info>
+
+# Server-side
+<reply>
+
+<data>
+HTTP/1.1 200 OK
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Content-Length: 0
+Set-Cookie: ckyPersistent=permanent;path=;path=/
+
+</data>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP cookie with path set twice
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/1161 -c log/cookies1161.txt
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+GET /1161 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Accept: */*
+
+</protocol>
+<file name="log/cookies1161.txt">
+# Netscape HTTP Cookie File
+# https://curl.haxx.se/docs/http-cookies.html
+# This file was generated by libcurl! Edit at your own risk.
+
+127.0.0.1	FALSE	/	FALSE	0	ckyPersistent	permanent
+</file>
+</verify>
+</testcase>