Under a constant subject: an upload's random volume stem, and an image's set head

- "[ TOWN ] [ www town ag ] [ TV ] … "Z3mMTMPsoT4ikE_Di3fKnNF21.part01.rar"",
  "….vol4+4.par2": the subject and the total were the key, so every upload of
  a total was one release (2,338 files for 20; also partner-of-ssl-news,
  brothers-of-usenet). A random stem (no dots or spaces) on a volume file
  joins the subject key; a scene name doesn't, so its nfo stays.
- "Molly Set [i/50] "mo103x003.jpg"": every set of 50 was one. An image's
  name up to its first number, when another follows, joins the key.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

edge/src/names.rs

@@ -813,8 +813,21 @@ pub fn release_identity(poster: &str, subject: &str, name: &str) -> Release {
     let one_word = image && remainder.len() >= 3 && remainder.bytes().all(|c| c.is_ascii_alphabetic());
     if !tag && (names_release(&remainder) || one_word) {
         // Without a counter an image's set: its name up to its last number, digits kept; none without numbers.
-        let bound = total.clone().unwrap_or_else(|| if image { image_set(&stem) } else { String::new() });
-        return Release { key: hash(&["subject", poster, &remainder, &bound]), name: remainder, source: "subject", file_total };
+        let set = if image { image_set(&stem) } else { String::new() };
+        let bound = total.clone().unwrap_or_else(|| set.clone());
+        let mut parts: Vec<&str> = vec!["subject", poster, &remainder, &bound];
+        // An image's set as well under a counter ("Molly Set" [i/50]: "mo103x003.jpg"): its name up to its first number,
+        // when another follows (/^(\D*\d+)\D+\d+/).
+        let head = if image && total.is_some() { SET_HEAD.captures(stem.as_bytes()).map(|c| String::from_utf8(c[1].to_vec()).unwrap()) } else { None };
+        if let Some(h) = head.as_deref() {
+            parts.push(h);
+        }
+        // An upload's random stem on its volumes ("Z3mMTMPsoT4ikE_Di3fKnNF21.part01.rar" under "[ TOWN ] … [ TV ]").
+        let stripped: String = stem.chars().filter(|c| !matches!(c, '-' | '_')).collect();
+        if !image && test(&RANDOM_VOLUME, name) && stem.bytes().all(|c| c.is_ascii_alphanumeric() || c == b'_' || c == b'-') && looks_random(&stripped) {
+            parts.push(&stem);
+        }
+        return Release { key: hash(&parts), name: remainder, source: "subject", file_total };
     }
     if let Some(total) = post_total.filter(|&n| n != 0 && !tag) {
         if is_post_token(&remainder) {
@@ -918,6 +931,10 @@ static SCENE_TRACK: LazyLock<Regex> = LazyLock::new(|| re(r"^[0-9]{1,3}[-_ .]+(.
 static SCENE_RELEASE: LazyLock<Regex> = LazyLock::new(|| {
     re(r"(?i)^(.+?)(?:_-_| - |-).*-(?:web|cd[a-z]?|vinyl|vls|sat|cable|fm|dab|single|ep|lp|promo|bootleg)-.*(?:19|20)[0-9]{2}(?:-[A-Za-z0-9_]+)?$")
 });
+/// RANDOM_VOLUME (lib/release/identity.ts): a file of a multi-volume upload.
+static RANDOM_VOLUME: LazyLock<Regex> = LazyLock::new(|| re(r"(?i)\.(?:part[0-9]+\.rar|vol[0-9]+[+-][0-9]+\.par2|par2|r[0-9]{2,3}|7z\.[0-9]{3}|zip\.[0-9]{3}|[0-9]{3})$"));
+/// An image's set head (lib/release/identity.ts): its name up to its first number, when another follows.
+static SET_HEAD: LazyLock<Regex> = LazyLock::new(|| re(r"^([^0-9]*[0-9]+)[^0-9]+[0-9]+"));
 static VOLUME_NUMBER: LazyLock<Regex> = LazyLock::new(|| re(r"^(.*[^0-9. ])[. ]([0-9]{1,5})\.?$"));
 
 static GENERIC: LazyLock<Regex> = LazyLock::new(|| {
@@ -1567,6 +1584,14 @@ mod image_set_tests {
             lop("022", "457", "r86_022 - Gwen Guthrie - Ain't Nothing Going on but the Rent.mp3").key,
             lop("022", "333", "r98_333 - Jellie - Roller Coaster.mp3").key
         );
+        let town = |i: &str, n: &str| super::release_identity("Kim <Jong-Un@town.ag>", &format!(r#"[ TOWN ] [ www.town.ag ] [ TV ] [{i}/20] - "{n}" yEnc"#), n);
+        assert_eq!(town("01", "Z3mMTMPsoT4ikE_Di3fKnNF21.part01.rar").key, town("18", "Z3mMTMPsoT4ikE_Di3fKnNF21.vol4+4.par2").key);
+        assert_ne!(town("01", "Z3mMTMPsoT4ikE_Di3fKnNF21.part01.rar").key, town("01", "i3DpbaTUJT4L6V48fEBdbVV46.part01.rar").key);
+        let show = |i: &str, n: &str| super::release_identity("p", &format!(r#"Some.Show.S01E01 [{i}/20] - "{n}" yEnc"#), n);
+        assert_eq!(show("01", "The.Big.Bang.Theory.S01E01.part01.rar").key, show("20", "The.Big.Bang.Theory.S01E01.nfo").key);
+        let molly = |i: &str, n: &str| super::release_identity("p", &format!(r#"Molly Set [{i}/50] - "{n}" yEnc"#), n);
+        assert_eq!(molly("01", "mo103x003.jpg").key, molly("02", "mo103x004.jpg").key);
+        assert_ne!(molly("01", "mo103x003.jpg").key, molly("01", "mop120x032.jpg").key);
         let mdg = |post: &str, i: &str, n: &str| super::release_identity("p", &format!(r#"{post} - ({i}/90) "{n}" - 16,14 MB - yEnc"#), n);
         assert_eq!(mdg("MDG005b", "01", "IMG_2307.JPG").key, mdg("MDG005b", "02", "IMG_2308.jpg").key);
         assert_ne!(mdg("MDG005b", "01", "IMG_2307.JPG").key, mdg("MDG006a", "01", "IMG_4410.JPG").key);