mime: clone mime tree upon easy handle duplication.

A mime tree attached to an easy handle using CURLOPT_MIMEPOST is
strongly bound to the handle: there is a pointer to the easy handle in
each item of the mime tree and following the parent pointer list
of mime items ends in a dummy part stored within the handle.

Because of this binding, a mime tree cannot be shared between different
easy handles, thus it needs to be cloned upon easy handle duplication.

There is no way for the caller to get the duplicated mime tree
handle: it is then set to be automatically destroyed upon freeing the
new easy handle.

New test 654 checks proper mime structure duplication/release.

Add a warning note in curl_mime_data_cb() documentation about sharing
user data between duplicated handles.

Closes #2235

2 files changed, 110 insertions, 1 deletions

diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index 5fd35eff5..7e3ca25d5 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -80,7 +80,7 @@ test617 test618 test619 test620 test621 test622 test623 test624 test625 \
 test626 test627 test628 test629 test630 test631 test632 test633 test634 \
 test635 test636 test637 test638 test639 test640 test641 test642 \
 test643 test644 test645 test646 test647 test648 test649 test650 test651 \
-test652 test653 \
+test652 test653 test654 \
 \
 test700 test701 test702 test703 test704 test705 test706 test707 test708 \
 test709 test710 test711 test712 test713 test714 test715 \
diff --git a/tests/data/test654 b/tests/data/test654
new file mode 100644
index 000000000..21697e763
--- /dev/null
+++ b/tests/data/test654
@@ -0,0 +1,109 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+HTTP MIME POST
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</data>
+<datacheck>
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+HTTP/1.1 200 OK

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Server: test-server/fake swsclose

+Connection: close

+Content-Type: text/html

+

+hello
+</datacheck>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+# tool is what to use instead of 'curl'
+<tool>
+lib654
+</tool>
+
+ <name>
+HTTP duplicate easy handle with mime data
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/654
+</command>
+<file name="log/file654.txt">
+This is data from a file
+</file>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strippart>
+s/^--------------------------[a-z0-9]*/------------------------------/
+s/boundary=------------------------[a-z0-9]*/boundary=----------------------------/
+</strippart>
+# Note that the stripping above removes 12 bytes from every occurrence of the
+# boundary string and since 5 of them are in the body contents, we see
+# (5*12) == 60 bytes less
+<protocol>
+POST /654 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 0

+

+POST /654 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Transfer-Encoding: chunked

+Content-Type: multipart/form-data; boundary=----------------------------

+Expect: 100-continue

+

+20c

+------------------------------

+Content-Disposition: form-data; name="greeting"

+Content-Type: application/X-Greeting

+Content-Transfer-Encoding: base64

+X-Test-Number: 654

+

+aGVsbG8=

+------------------------------

+Content-Disposition: form-data; filename="file654.txt"

+Content-Type: text/plain

+

+This is data from a file
+

+------------------------------

+Content-Disposition: form-data

+

+this is what we post to the silly web server
+

+--------------------------------

+

+0

+

+</protocol>
+</verify>
+</testcase>