plugin: plumb file token with acme isfilec expansion

Replace Document::wordAt() in plumbAtCursor() with fileTokenAt(), an
acme-style button-3 file expansion: grow over isFileChar() (alnum, '_',
and '. - + / : @', matching plan9port acme's isfilec), with ':' ending
the file name and only a digit-led ':line[:col]' suffix kept attached.
This grabs whole paths like /a/b/dpg_identity.php:584 under the caret.
Also reverts the earlier ^W change so acmeEraseWord again matches acme's
C isalnum (which excludes '_').

docs/PLAN.md

@@ -348,7 +348,10 @@ Kate flow through the real plumber rules.
 - **Plugin wiring** (`src/plugin/ollieplugin.cpp`): an `ollie_plumb` QAction on
   **F2** (testing trigger; a function key, so no collision with the Alt+letter
   door policy — final gesture will be RMB). `plumbAtCursor()` plumbs the
-  selection, else `Document::wordAt(cursorPosition)`, with the active doc's dir
+  selection, else the acme-style file-path token under the caret
+  (`fileTokenAt` + `isFileChar`, matching plan9port acme's `isfilec`: alnum,
+  `_`, and `. - + / : @`; `:` ends the file name and only a digit-led
+  `:line[:col]` suffix is kept), with the active doc's dir
   as `wdir`; on send failure it falls back to an internal resolver (URL →
   `QDesktopServices`, path[:line] → open here). Incoming `edit` messages are
   opened via `MainWindow::openUrl` + `activateView` + `setCursorPosition`; a

src/plugin/ollieplugin.cpp

@@ -99,6 +99,29 @@ bool isQuote(QChar c)
     return u == '\'' || u == '"' || u == '`';
 }
 
+// Characters that may appear in a plumbable file path, mirroring plan9port
+// acme's isfilec() (look.c). Acme treats a rune as a file char when its
+// isalnum() is true OR it is one of ". - + / : @". Acme's isalnum() counts '_'
+// as alphanumeric (it is not in acme's punctuation set), so '_' is a file char;
+// QChar::isLetterOrNumber() excludes it, hence the explicit test.
+bool isFileChar(QChar c)
+{
+    if (c.isLetterOrNumber() || c == QLatin1Char('_')) {
+        return true;
+    }
+    switch (c.unicode()) {
+    case '.':
+    case '-':
+    case '+':
+    case '/':
+    case ':':
+    case '@':
+        return true;
+    default:
+        return false;
+    }
+}
+
 // Advance a cursor by one character, wrapping across line ends. Returns false
 // at end of document.
 bool stepForward(KTextEditor::Document *doc, KTextEditor::Cursor &c)
@@ -213,6 +236,51 @@ KTextEditor::Cursor findQuoteBackward(KTextEditor::Document *doc, int line, int
     return KTextEditor::Cursor::invalid();
 }
 
+// Expand the caret position into the surrounding file-path token, mirroring
+// plan9port acme's button-3 file expansion (look.c). Grow left and right over
+// isFileChar() runs, but treat ':' as acme does: it ends the file name and may
+// introduce a numeric ":line[:col]" address, which is kept attached to the
+// token (the plumber / onPlumbEdit splits it downstream). Expansion is
+// line-local; acme stops at white space and a newline is never a file char.
+QString fileTokenAt(KTextEditor::Document *doc, const KTextEditor::Cursor &at)
+{
+    const int line = at.line();
+    const int len = doc->lineLength(line);
+    auto ch = [&](int c) { return doc->characterAt(KTextEditor::Cursor(line, c)); };
+    auto isFileNoColon = [&](QChar c) { return isFileChar(c) && c != QLatin1Char(':'); };
+
+    // File name: grow left and right over file chars, stopping before any ':'
+    // (acme ends the name at the colon and parses an address after it).
+    int lo = at.column();
+    int hi = at.column();
+    while (hi < len && isFileNoColon(ch(hi))) {
+        ++hi;
+    }
+    while (lo > 0 && isFileNoColon(ch(lo - 1))) {
+        --lo;
+    }
+    if (hi <= lo) {
+        return QString();
+    }
+
+    // Optional ":line[:col]" address: only when the colon is immediately
+    // followed by a digit, matching acme's isaddrc gate and the numeric suffix
+    // onPlumbEdit expects. Consume up to two colon-separated digit runs.
+    int end = hi;
+    for (int part = 0; part < 2 && end < len && ch(end) == QLatin1Char(':'); ++part) {
+        int scan = end + 1;
+        if (scan >= len || !ch(scan).isDigit()) {
+            break; // ':' not introducing a number — leave it out of the token
+        }
+        while (scan < len && ch(scan).isDigit()) {
+            ++scan;
+        }
+        end = scan;
+    }
+
+    return doc->text(KTextEditor::Range(line, lo, line, end));
+}
+
 // Prefix marking a palette id that is a ":" command string to execute rather
 // than a QAction to trigger.
 const QLatin1String kCmdPrefix("ollie:cmd:");
@@ -873,14 +941,15 @@ void OllieView::plumbAtCursor()
     }
 
     // What to plumb: an explicit selection wins (lets the user plumb a path
-    // with a line suffix like "foo.cpp:42"), otherwise the word under the
-    // caret.
+    // with a line suffix like "foo.cpp:42"), otherwise the file-path token
+    // under the caret, expanded acme-style (isFileChar: alnum, '_', and
+    // ". - + / : @") so paths and their ":line" address are grabbed whole.
     QString data;
     if (view->selection()) {
         data = view->selectionText().trimmed();
     }
     if (data.isEmpty()) {
-        data = doc->wordAt(view->cursorPosition());
+        data = fileTokenAt(doc, view->cursorPosition());
     }
     if (data.isEmpty()) {
         return;
@@ -1702,9 +1771,7 @@ void OllieView::acmeEraseWord()
             break;
         }
         const QChar r = doc->characterAt(prev);
-        // Acme's isalnum() treats '_' as a word character (it is not in acme's
-        // punctuation set), so ^W does not stop on underscores.
-        const bool alnum = r.isLetterOrNumber() || r == QLatin1Char('_');
+        const bool alnum = r.isLetterOrNumber();
         if (alnum && skipping) {
             skipping = false;
         } else if (!alnum && !skipping) {