Fix char-selector parsing when the length is an expression containing a comma

CHANGELOG.md

@@ -22,6 +22,10 @@ Modifications by (in alphabetical order):
 * P. Vitt, University of Siegen, Germany
 * A. Voysey, UK Met Office
 
+16/07/2026 PR #520 for #519. Fix truncation of a character length expression that
+           contains a comma (e.g. the arguments to an intrinsic such as
+           MAX) when the kind appears before the length in a char-selector.
+
 25/06/2026 PR #514 towards #428. Add some Fortran2008-only intrinsics.
 
 19/06/2026 PR #513 for #512. Fix circular import in Fortran2008.

src/fparser/two/Fortran2003.py

@@ -1534,7 +1534,7 @@ def match(string: str):
             line = line[1:].lstrip()
             i = line.find(",")
             if i == -1:
-                return None, Scalar_Int_Initialization_Expr(line)
+                return None, Scalar_Int_Initialization_Expr(repmap(line))
             v = line[i + 1 :].lstrip()
             line = line[:i].rstrip()
             if v[:3].upper() != "LEN":
@@ -1543,6 +1543,8 @@ def match(string: str):
             if not v.startswith("="):
                 return
             v = v[1:].lstrip()
+            v = repmap(v)
+            line = repmap(line)
             return Type_Param_Value(v), Scalar_Int_Initialization_Expr(line)
 
         i = line.find(",")
@@ -1553,6 +1555,8 @@ def match(string: str):
         if line[:4].upper() == "KIND" and line[4:].lstrip().startswith("="):
             line = line[4:].lstrip()
             line = line[1:].lstrip()
+        v = repmap(v)
+        line = repmap(line)
         return Type_Param_Value(v), Scalar_Int_Initialization_Expr(line)
 
     def tostr(self):

src/fparser/two/tests/test_fortran2003.py

@@ -458,6 +458,21 @@ def test_char_selector():  # R424
     assert isinstance(obj, tcls), repr(obj)
     assert str(obj) == "(LEN = 2, KIND = 8)"
 
+    # A length that is itself an expression containing a comma (e.g. the
+    # arguments to an intrinsic) must survive the splitting of the kind and
+    # length parts of the selector. The kind-first and positional forms of
+    # the selector previously left the length expression truncated at the
+    # inner comma.
+    obj = tcls("(kind=8,len=max(2, 0))")
+    assert isinstance(obj, tcls), repr(obj)
+    assert str(obj) == "(LEN = MAX(2, 0), KIND = 8)"
+    assert "F2PY" not in repr(obj)
+
+    obj = tcls("(max(2, 0),8)")
+    assert isinstance(obj, tcls), repr(obj)
+    assert str(obj) == "(LEN = MAX(2, 0), KIND = 8)"
+    assert "F2PY" not in repr(obj)
+
 
 def test_complex_literal_constant():  # R421
     tcls = Complex_Literal_Constant