tests: replace strcpy() with curlx_strcopy()

Also:
- examples/hsts-preload: apply the same change as it's based on lib1915
  in tests. Make a local clone of `curlx_strcopy()`. Then drop the
  `_CRT_SECURE_NO_WARNINGS` hack, that's no longer necessary.
- curl_setup.h: delete `strcpy()` from the `_CRT_SECURE_NO_WARNINGS`
  list.

Closes #20076

tests/server/getpart.c

@@ -391,19 +391,19 @@ int getpart(char **outbuf, size_t *outlen,
 
       if(STATE_OUTSIDE == state) {
         /* outermost element (<testcase>) */
-        strcpy(curouter, ptag);
+        curlx_strcopy(curouter, sizeof(curouter), ptag, strlen(ptag));
         state = STATE_OUTER;
         continue;
       }
       else if(STATE_OUTER == state) {
         /* start of a main section */
-        strcpy(curmain, ptag);
+        curlx_strcopy(curmain, sizeof(curmain), ptag, strlen(ptag));
         state = STATE_INMAIN;
         continue;
       }
       else if(STATE_INMAIN == state) {
         /* start of a sub section */
-        strcpy(cursub, ptag);
+        curlx_strcopy(cursub, sizeof(cursub), ptag, strlen(ptag));
         state = STATE_INSUB;
         if(!strcmp(curmain, main) && !strcmp(cursub, sub)) {
           /* start of wanted part */

tests/server/socksd.c

@@ -101,9 +101,12 @@ static void socksd_resetdefaults(void)
   s_config.reqcmd = CONFIG_REQCMD;
   s_config.connectrep = CONFIG_CONNECTREP;
   s_config.port = CONFIG_PORT;
-  strcpy(s_config.addr, CONFIG_ADDR);
-  strcpy(s_config.user, "user");
-  strcpy(s_config.password, "password");
+  curlx_strcopy(s_config.addr, sizeof(s_config.addr),
+                CONFIG_ADDR, strlen(CONFIG_ADDR));
+  curlx_strcopy(s_config.user, sizeof(s_config.user),
+                "user", strlen("user"));
+  curlx_strcopy(s_config.password, sizeof(s_config.password),
+                "password", strlen("password"));
 }
 
 static void socksd_getconfig(void)
@@ -141,7 +144,8 @@ static void socksd_getconfig(void)
           }
         }
         else if(!strcmp(key, "backend")) {
-          strcpy(s_config.addr, value);
+          curlx_strcopy(s_config.addr, sizeof(s_config.addr),
+                        value, strlen(value));
           logmsg("backend [%s] set", s_config.addr);
         }
         else if(!strcmp(key, "backendport")) {
@@ -152,11 +156,13 @@ static void socksd_getconfig(void)
           }
         }
         else if(!strcmp(key, "user")) {
-          strcpy(s_config.user, value);
+          curlx_strcopy(s_config.user, sizeof(s_config.user),
+                        value, strlen(value));
           logmsg("user [%s] set", s_config.user);
         }
         else if(!strcmp(key, "password")) {
-          strcpy(s_config.password, value);
+          curlx_strcopy(s_config.password, sizeof(s_config.password),
+                        value, strlen(value));
           logmsg("password [%s] set", s_config.password);
         }
         /* Methods:

tests/server/util.c

@@ -694,7 +694,7 @@ int bind_unix_socket(curl_socket_t sock, const char *unix_socket,
     logmsg("Too long unix socket domain path (%zd)", len);
     return -1;
   }
-  strcpy(sau->sun_path, unix_socket);
+  curlx_strcopy(sau->sun_path, sizeof(sau->sun_path), unix_socket, len);
   rc = bind(sock, (struct sockaddr *)sau, sizeof(struct sockaddr_un));
   if(rc && SOCKERRNO == SOCKEADDRINUSE) {
     struct_stat statbuf;