Hi! Thanks for review.

On ÁÑ, äÕÒ 16, 2019 at 12:17 AM, Vladislav Shpilevoy 
<v.shpilevoy@tarantool.org> wrote:
> Hi!
> 
>>>         5. Out of 80 symbols. 
>>> 2. Still out of 80.
>> My text editor shows 70 symbols.
>> 
> 
> Then there is something wrong with your editor, sorry.
> 
> https://github.com/tarantool/tarantool/blob/romanhabibov/gh-3679-httpc-request/src/lua/httpc.c#L180
> 
> Lets count. Here you have 6 tabs - 6 * 8 = 48 symbols. Then you have 
> 55 symbols of
> 
>     "headers must be string or table with \"__tostring\"");
> 
> 48 + 55 = 103.
> 
> Also, the error string is not aligned by opening parenthesis.
> 
> In your email I see, that you have 4 symbols tab, what gives you 79 
> symbols, but
> tab width in this file should be 8. So probably you mistakenly set 
> tab width to
> 4 and the editor shows you < 80 width. Please, fix.
> 
Ok. Done.

commit c9802592b27cb6986e3e72eb948d8dbfb21baa7e
Author: Roman Khabibov <roman.habibov@tarantool.org>
Date:   Wed Dec 26 17:49:34 2018 +0300

    httpc: add checking of headers in httpc:request

    Add preprocessing of the request headers. Each header must be 
'string' or 'table'
    with '__tostring' metamethod.

    Closes #3679

diff --git a/src/lua/httpc.c b/src/lua/httpc.c
index 5f4e2e912..fb012f58b 100644
--- a/src/lua/httpc.c
+++ b/src/lua/httpc.c
@@ -173,6 +173,18 @@ luaT_httpc_request(lua_State *L)
 	if (!lua_isnil(L, -1)) {
 		lua_pushnil(L);
 		while (lua_next(L, -2) != 0) {
+			int header_type = lua_type(L, -1);
+			if (header_type != LUA_TSTRING) {
+				char *err_msg = "headers must be " \
+				"string or table with \"__tostring\"";
+				if (header_type != LUA_TTABLE) {
+					return luaL_error(L, err_msg);
+				} else if (!luaL_getmetafield(L, -1,
+							      "__tostring")) {
+					return luaL_error(L, err_msg);
+				}
+				lua_pop(L, 1);
+			}
 			if (httpc_set_header(req, "%s: %s",
 					     lua_tostring(L, -2),
 					     lua_tostring(L, -1)) < 0) {
diff --git a/test/app-tap/http_client.test.lua 
b/test/app-tap/http_client.test.lua
index 10a3728f8..8a98d1e92 100755
--- a/test/app-tap/http_client.test.lua
+++ b/test/app-tap/http_client.test.lua
@@ -205,6 +205,80 @@ local function test_errors(test)
     test:is(r.status, 595, "GET: response on bad url")
 end

+-- gh-3679 allow only headers can be converted to string
+local function test_request_headers(test, url, opts)
+    local exp_err = 'headers must be string or table with "__tostring"'
+    local cases = {
+        {
+            'string header',
+            opts = {headers = {aaa = 'aaa'}},
+            exp_err = nil,
+        },
+        {
+            'header with __tostring() metamethod',
+            opts = {headers = {aaa = setmetatable({}, {
+                __tostring = function(self)
+                    return 'aaa'
+                end})}},
+            exp_err = nil,
+            postrequest_check = function(opts)
+                assert(type(opts.headers.aaa) == 'table',
+                    '"aaa" header was modified in http_client')
+            end,
+        },
+        {
+            'boolean header',
+            opts = {headers = {aaa = true}},
+            exp_err = exp_err,
+        },
+        {
+            'number header',
+            opts = {headers = {aaa = 10}},
+            exp_err = exp_err,
+        },
+        {
+            'cdata header (box.NULL)',
+            opts = {headers = {aaa = box.NULL}},
+            exp_err = exp_err,
+        },
+        {
+            'cdata<uint64_t> header',
+            opts = {headers = {aaa = 10ULL}},
+            exp_err = exp_err,
+        },
+        {
+            'table header w/o metatable',
+            opts = {headers = {aaa = {}}},
+            exp_err = exp_err,
+        },
+        {
+            'table header w/o __tostring() metamethod',
+            opts = {headers = {aaa = setmetatable({}, {})}},
+            exp_err = exp_err,
+        },
+    }
+    test:plan(#cases)
+
+    local http = client:new()
+
+    for _, case in ipairs(cases) do
+        local opts = merge(table.copy(opts), case.opts)
+        local ok, err = pcall(http.get, http, url, opts)
+        if case.postrequest_check ~= nil then
+            case.postrequest_check(opts)
+        end
+        if case.exp_err == nil then
+            -- expect success
+            test:ok(ok, case[1])
+        else
+            -- expect fail
+            assert(type(err) == 'string')
+            err = err:gsub('^builtin/[a-z._]+.lua:[0-9]+: ', '')
+            test:is_deeply({ok, err}, {false, case.exp_err}, case[1])
+        end
+    end
+end
+
 local function test_headers(test, url, opts)
     test:plan(19)
     local http = client:new()
@@ -397,12 +471,13 @@ local function test_concurrent(test, url, opts)
 end

 function run_tests(test, sock_family, sock_addr)
-    test:plan(9)
+    test:plan(10)
     local server, url, opts = start_server(test, sock_family, 
sock_addr)
     test:test("http.client", test_http_client, url, opts)
     test:test("cancel and errinj", test_cancel_and_errinj, url .. 
'long_query', opts)
     test:test("basic http post/get", test_post_and_get, url, opts)
     test:test("errors", test_errors)
+    test:test("request_headers", test_request_headers, url, opts)
     test:test("headers", test_headers, url, opts)
     test:test("special methods", test_special_methods, url, opts)
     if sock_family == 'AF_UNIX' and jit.os ~= "Linux" then