From d296c2d1d590f8b4f619d9c555ff24ddecec1614 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Tue, 21 May 2024 15:55:06 +0200 Subject: vmime: prevent loss of a space during text::createFromString (#306) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ``` mailbox(text("Test München West", charsets::UTF_8), "a@b.de").generate(); ``` produces ``` =?us-ascii?Q?Test_?= =?utf-8?Q?M=C3=BCnchen?= =?us-ascii?Q?West?= ``` The first space between ``Test`` and ``München`` is encoded as an underscore along with the first word: ``Test_``. The second space between ``München`` and ``West`` is encoded with neither of the two words and thus lost. Decoding the text results in ``Test MünchenWest`` instead of ``Test München West``. This is caused by how ``vmime::text::createFromString()`` handles transitions between 7-bit and 8-bit words: If an 8-bit word follows a 7-bit word, a space is appended to the previous word. The opposite case of a 7-bit word following an 8-bit word *misses* this behaviour. When one fixes this problem, a follow-up issue appears: ``text::createFromString("a b\xFFc d")`` tokenizes the input into ``m_words={word("a "), word("b\xFFc ", utf8), word("d")}``. This "right-side alignment" nature of the whitespace is a problem for word::generate(): As per RFC 2047, spaces between adjacent encoded words are just separators but not meant to be displayed. A space between an encoded word and a regular ASCII text is not just a separator but also meant to be displayed. When word::generate() outputs the b-word, it would have to strip one space, but only when there is a transition from encoded-word to unencoded word. word::generate() does not know whether d will be encoded or unencoded. The idea now is that we could change the tokenization of ``text::createFromString`` such that whitespace is at the *start* of words rather than at the end. With that, word::generate() need not know anything about the next word, but rather only the *previous* one. Thus, in this patch, 1. The tokenization of ``text::createFromString`` is changed to left-align spaces and the function is fixed to account for the missing space on transition. 2. ``word::generate`` learns how to steal a space character. 3. Testcases are adjusted to account for the shifted position of the space. Fixes: #283, #284 Co-authored-by: Vincent Richard --- tests/parser/mailboxTest.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'tests/parser/mailboxTest.cpp') diff --git a/tests/parser/mailboxTest.cpp b/tests/parser/mailboxTest.cpp index 997a6a38..d1af23f2 100644 --- a/tests/parser/mailboxTest.cpp +++ b/tests/parser/mailboxTest.cpp @@ -32,6 +32,7 @@ VMIME_TEST_SUITE_BEGIN(mailboxTest) VMIME_TEST(testSeparatorInComment) VMIME_TEST(testMalformations) VMIME_TEST(testExcessiveQuoting) + VMIME_TEST(testSpacing) VMIME_TEST_LIST_END @@ -184,4 +185,13 @@ VMIME_TEST_SUITE_BEGIN(mailboxTest) VASSERT_EQ("generate", "=?utf-8?Q?Foo_B=40r?= ", a->generate()); } + void testSpacing() { + + vmime::text t("Foo B\xc3\xa4renstark Baz", vmime::charsets::UTF_8); + vmime::mailbox m(t, "a@b.de"); + VASSERT_EQ("1", "Foo =?utf-8?Q?B=C3=A4renstark?= Baz", t.generate()); + VASSERT_EQ("2", "=?us-ascii?Q?Foo?= =?utf-8?Q?_B=C3=A4renstark?= =?us-ascii?Q?_Baz?= ", m.generate()); + + } + VMIME_TEST_SUITE_END -- cgit v1.2.3