[2678] Send multiple headers for url-encoded and multipart-form bodies

[ilia1243]

Motivation:

Multiple headers are not sent with url-encoded and multipart-form bodies.

Solution:

Change resolution of headers in HttpContext#handleCreateRequest(). Do not use MultiMap#get() to copy headers anymore. Instead, copy the entries from the original MultiMap using MultiMap#addAll(MultiMap).

Fixes #2678

[ilia1243]

Actually, I do not quite understand why headers are copied twice. See

vertx-web/vertx-web-client/src/main/java/io/vertx/ext/web/client/impl/HttpRequestImpl.java

Line 538 in 2a661ad

void mergeHeaders(RequestOptions options) {

)

Without the second copying all tests are also passed. Check test commit ilia1243@f470308

Though I see some activity with this code

1. 8c482962
2. 4ea2fb35

I did not remove this part, because do not see the whole picture. Please comment if this can be removed.

[tsegismont]

Indeed, adding the request headers again looks redundant. You could replace line 446-451 in the original file with:

for (Map.Entry<String, String> header : multipartForm.headers()) {
          requestOptions.putHeader(header.getKey(), header.getValue());
}

That would do (using forEach here implies creating a lamba on each call and does not bring anything).

[tsegismont]

Thank you @ilia1243 , good stuff

[tsegismont]

Indeed, adding the request headers again looks redundant. You could replace line 446-451 in the original file with:

for (Map.Entry<String, String> header : multipartForm.headers()) {
          requestOptions.putHeader(header.getKey(), header.getValue());
}

That would do (using forEach here implies creating a lamba on each call and does not bring anything).

[tsegismont]

Considering the comments related to HttpContext you can revert changes in this file.