check: stamp SK_TYPE value idents with the per-decl NAMED

A TYPE name used as a VALUE (an error-singleton `return too_long;`)
stamped the flattened BODY type, so structurally identical !void
singletons in one union were indistinguishable and flatvariantidxt
loud-rejected the ambiguity — the real cause of the lib/path wwstage
reject (the pinned #120/#29 global-slice-const blame was stale; that
family had drained). The N_IDENT arm resolves through a synthesized
TNAME (the #66 N_STRUCTLIT precedent); the module-qualified N_DOT twin
reads the sym's cached NAMED. Graduates the path M_WWREJECT pin (#142).

internal/wwfixture/types.ww

@@ -1,13 +1,13 @@
 package wwfixture;
 
 def protocolversion: i32 = 1;
-def corpuscount: i32 = 1237;
+def corpuscount: i32 = 1238;
 def errorcount: i32 = 314;
 def compilecount: i32 = 12;
 def runcount: i32 = 145;
-def runexitcount: i32 = 766;
-def nativecount: i32 = 2474;
-def corpushash: str = "7763f2eb34524f67355114f5bdfbf3f64415152a8ec64060fe32a322bdbe1b24";
+def runexitcount: i32 = 767;
+def nativecount: i32 = 2476;
+def corpushash: str = "a78db801f50ad02de11fed981bd6d9c2d67509e69a69615744f1b2ad3ef4814d";
 
 type directive = enum i32 {
 	ERROR = 0,

selfhost/cmd/wcc/check.ww

@@ -3310,6 +3310,26 @@ fn exprtype(c: *checker, e: *syntax.node, hint: *syntax.node) *syntax.node = {
 			e.type_ = tinfofornode(c, ft): *void;
 			return ft;
 		};
+		// #142: a TYPE name used as a VALUE (an error-singleton
+		// `return too_long;`) must stamp the per-decl NAMED, not the
+		// flattened body — three structurally identical !void
+		// singletons in one union are indistinguishable by body, so
+		// flatvariantidxt's NAMED pass either mis-tags or
+		// loud-rejects as ambiguous. Resolve through a synthesized
+		// TNAME to reuse tinfofornode's TY_NAMED build/cache (the
+		// SAME NAMED ptr the union variant resolved to) — the #66
+		// N_STRUCTLIT precedent verbatim; cstage mirror
+		// cmd/wcc/check.c:1414 `n->type = s->type`. The BODY node
+		// still returns so AST-level assign/return checks keep
+		// their prior input.
+		if (s.skind == syntax.skind.SK_TYPE) {
+			let tnm: *syntax.node = mktname(c, e.str);
+			let nti: *syntax.tinfo = tinfofornode(c, tnm);
+			if (nti != nil) {
+				e.type_ = nti: *void;
+				return s.decl.lhs;
+			};
+		};
 		let t: *syntax.node = s.decl.lhs;
 		// Propagate the declared type's tinfo onto the use site so
 		// downstream cgen walkers can read n.type_ off an ident.
@@ -3878,6 +3898,19 @@ fn exprtype(c: *checker, e: *syntax.node, hint: *syntax.node) *syntax.node = {
 							e.type_ = tinfofornode(c, ft): *void;
 							return ft;
 						};
+						// #142 twin of the N_IDENT SK_TYPE arm: a
+						// module-qualified TYPE name used as a VALUE
+						// (`mod.too_long`) stamps the per-decl NAMED.
+						// The sym caches its NAMED (tinfofornode
+						// N_TNAME arm) once any type-position ref
+						// resolved; a nil cache falls through to the
+						// prior body stamp.
+						if (fs.skind == syntax.skind.SK_TYPE) {
+							if (fs.type_ != nil) {
+								e.type_ = fs.type_: *void;
+								return fs.decl.lhs;
+							};
+						};
 						let tn: *syntax.node = fs.decl.lhs;
 						if (tn != nil) {
 							e.type_ = tinfofornode(c, tn): *void;

test/wcc/989_lib_byteid.c

@@ -117,14 +117,16 @@ static const struct ent ents[] = {
 	/* fixtureless modules, import-probe shape */
 	{ .probe = "package main;\nimport sort;\nfn main() i32 = { return 0; };\n",
 	  .mode = M_ID, .sentinel = "package sort;", .moddir = "lib/sort" },
-	/* c2-stack path::buffer realignment: w6c compiles, w6c_ww rejects
-	 * path's module-global slice consts (const dot/dotdot: []u8) = the
-	 * #120/#29 acceptance divergence (module-level composite globals);
-	 * + the #148 twin #151 (global []u8 by-value arg). Both → #125
-	 * batch. cstage runtime is covered by 989_path_run. M_WWREJECT
-	 * self-graduates: flips RED to M_ID the day wwstage accepts this. */
+	/* #142 graduated (the old #120/#29 global-slice-const blame was
+	 * stale — that family drained earlier): path declares three
+	 * structurally identical !void error singletons, and a VALUE use
+	 * (`return too_long;`) stamped the flattened BODY type, so
+	 * flatvariantidxt loud-rejected the ambiguity. The SK_TYPE value
+	 * arms now stamp the per-decl NAMED (the #66 N_STRUCTLIT
+	 * precedent). Runtime pin: r142_singleton_value_named. */
 	{ .probe = "package main;\nimport path;\nfn main() i32 = { return 0; };\n",
-	  .mode = M_WWREJECT, .cite = "#120/#29", .sentinel = "package path;", .moddir = "lib/path" },
+	  .mode = M_ID, .cite = "#142 graduated by the SK_TYPE NAMED value stamp",
+	  .sentinel = "package path;", .moddir = "lib/path" },
 	{ .probe = "package main;\nimport endian;\nfn main() i32 = { return 0; };\n",
 	  .mode = M_ID, .sentinel = "package endian;", .moddir = "lib/endian" },
 	{ .probe = "package main;\nimport net;\nfn main() i32 = { return 0; };\n",

test/wcc/data/r142_singleton_value_named/case.ww

@@ -0,0 +1,23 @@
+//ww:run-exit 42
+// #142: a VALUE use of an error-singleton type name whose union has
+// structurally identical siblings. The pre-fix wwstage stamped the
+// flattened BODY type (!void), so flatvariantidxt could not pick a
+// variant and loud-rejected; the per-decl NAMED stamp discriminates.
+// Exit 42 proves the SECOND variant is selected, not the first.
+package main;
+
+type a = !void;
+type b = !void;
+type err = !(a | b);
+
+fn f() err = {
+	return b;
+};
+
+fn main() i32 = {
+	match (f()) {
+	case a => { return 41; };
+	case b => { return 42; };
+	};
+	return 9;
+};