fix: add utf-7 equivalent charset labels

Author: sftse

src/decoders/charsets/map.rs

@@ -161,6 +161,9 @@ fn primary_charset_decoder(charset: &[u8]) -> Option<fn(&[u8]) -> String> {
         "utf_16be" => decoder_utf16_be,
         "utf_16le" => decoder_utf16_le,
         "utf_7" => decoder_utf7,
+        "x_unicode_2_0_utf_7" => decoder_utf7,
+        "unicode_1_1_utf_7" => decoder_utf7,
+        "csunicode11utf7" => decoder_utf7,
         "windows_1250" => decoder_cp1250,
         "windows_1251" => decoder_cp1251,
         "windows_1252" => decoder_cp1252,

src/decoders/encoded_word.rs

@@ -149,6 +149,23 @@ mod tests {
                 "مرحبا بالعالم",
                 true,
             ),
+            // utf-7 and equivalent charset labels from the charset crate
+            ("?utf-7?Q?Heinz_M+APw-ller?=", "Heinz Müller", true),
+            (
+                "?x-unicode-2-0-utf-7?Q?Heinz_M+APw-ller?=",
+                "Heinz Müller",
+                true,
+            ),
+            (
+                "?unicode-1-1-utf-7?Q?Heinz_M+APw-ller?=",
+                "Heinz Müller",
+                true,
+            ),
+            (
+                "?csunicode11utf7?Q?Heinz_M+APw-ller?=",
+                "Heinz Müller",
+                true,
+            ),
             #[cfg(feature = "full_encoding")]
             (
                 "?shift_jis?B?g26DjYFbgUWDj4Fbg4uDaA==?=",