melib: don't exclude whitespaces in mime encoded words

embed
Manos Pitsidianakis 2019-07-05 18:58:46 +03:00
parent ff2c030c0f
commit 6906142278
Signed by: Manos Pitsidianakis
GPG Key ID: 73627C2F690DF710
1 changed files with 60 additions and 10 deletions

View File

@ -1,18 +1,68 @@
use super::*;
use crate::grapheme_clusters::Graphemes;
pub fn encode_header(value: &str) -> String {
eprintln!("encoding \"{}\"", value);
let mut ret = String::with_capacity(value.len());
for word in value.split_whitespace() {
if word.is_ascii() {
ret.push_str(word);
} else {
ret.push_str(
format!("=?UTF-8?B?{}?=", BASE64_MIME.encode(word.trim().as_bytes())).trim(),
);
let graphemes = value.graphemes_indices();
let mut is_current_window_ascii = true;
let mut current_window_start = 0;
for (idx, g) in graphemes {
match (g.is_ascii(), is_current_window_ascii) {
(true, true) => {
ret.push_str(g);
}
(false, true) => {
current_window_start = idx;
is_current_window_ascii = false;
}
(true, false) => {
/* If !g.is_whitespace()
*
* Whitespaces inside encoded tokens must be greedily taken,
* instead of splitting each non-ascii word into separate encoded tokens. */
if !g.split_whitespace().collect::<Vec<&str>>().is_empty() {
ret.push_str(&format!(
"=?UTF-8?B?{}?=",
BASE64_MIME
.encode(value[current_window_start..idx].as_bytes())
.trim()
));
if idx != value.len() - 1 {
ret.push(' ');
}
is_current_window_ascii = true;
}
}
/* RFC2047 recommends:
* 'While there is no limit to the length of a multiple-line header field, each line of
* a header field that contains one or more 'encoded-word's is limited to 76
* characters.'
* This is a rough compliance.
*/
(false, false) if (((4 * (idx - current_window_start) / 3) + 3) & !3) > 33 => {
ret.push_str(&format!(
"=?UTF-8?B?{}?=",
BASE64_MIME
.encode(value[current_window_start..idx].as_bytes())
.trim()
));
if idx != value.len() - 1 {
ret.push(' ');
}
current_window_start = idx;
}
(false, false) => {}
}
ret.push(' ');
}
ret.pop();
/* If the last part of the header value is encoded, it won't be pushed inside the previous for
* block */
if !is_current_window_ascii {
ret.push_str(&format!(
"=?UTF-8?B?{}?=",
BASE64_MIME
.encode(value[current_window_start..].as_bytes())
.trim()
));
}
ret
}