Tweak parameter dependency test when typing applications (#23346)

Fixes #23299

Author: odersky

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -726,11 +726,14 @@ trait Applications extends Compatibility {
           def addTyped(arg: Arg): List[Type] =
             if !formal.isRepeatedParam then checkNoVarArg(arg)
             addArg(typedArg(arg, formal), formal)
-            if methodType.isParamDependent && typeOfArg(arg).exists then
-              // `typeOfArg(arg)` could be missing because the evaluation of `arg` produced type errors
-              formals1.mapconserve(safeSubstParam(_, methodType.paramRefs(n), typeOfArg(arg)))
-            else
-              formals1
+            if methodType.looksParamDependent
+                  // need to handle also false dependencies since we generate TypeTrees from
+                  // formal parameters in makeVarArg. These are not de-aliased, so they might contain
+                  // stray parameter references. Test case is i23266.scala.
+                && typeOfArg(arg).exists
+                  // `typeOfArg(arg)` could be missing because the evaluation of `arg` produced type errors
+            then formals1.mapconserve(safeSubstParam(_, methodType.paramRefs(n), typeOfArg(arg)))
+            else formals1
 
           def missingArg(n: Int): Unit =
             fail(MissingArgument(methodType.paramNames(n), methString))

compiler/test/dotc/pos-test-pickling.excludelist

@@ -139,6 +139,7 @@ parsercombinators-new-syntax.scala
 hylolib-deferred-given
 hylolib-cb
 hylolib
+i23266.scala
 
 # typecheckErrors method unpickling
 i21415.scala

tests/neg/i16842.check

@@ -1,16 +1,4 @@
--- [E007] Type Mismatch Error: tests/neg/i16842.scala:24:8 -------------------------------------------------------------
-24 |  Liter(SemanticArray[SemanticInt.type], x) // error // error
-   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |        Found:    Int => SemanticArray[SemanticInt.type]
-   |        Required: SemanticArray[SemanticType]
-   |
-   | longer explanation available when compiling with `-explain`
--- [E007] Type Mismatch Error: tests/neg/i16842.scala:24:41 ------------------------------------------------------------
-24 |  Liter(SemanticArray[SemanticInt.type], x) // error // error
-   |                                         ^
-   |                      Found:    (x : List[Expr2[SemanticInt.type]])
-   |                      Required: ty.T
-   |                      Note that implicit conversions were not tried because the result of an implicit conversion
-   |                      must be more specific than ty.T
-   |
-   | longer explanation available when compiling with `-explain`
+-- Error: tests/neg/i16842.scala:24:7 ----------------------------------------------------------------------------------
+24 |  Liter(SemanticArray[SemanticInt.type], x) // error
+   |       ^
+   |       invalid new prefix (dim: Int): SemanticArray[SemanticInt.type] cannot replace ty.type in type ty.T

tests/neg/i16842.scala

@@ -21,5 +21,5 @@ def typecheckArrayLiter(
     a: ArrayLiter
 ): Liter[SemanticArray[SemanticType]] = {
   val x: List[Expr2[SemanticInt.type]] = List()
-  Liter(SemanticArray[SemanticInt.type], x) // error // error
+  Liter(SemanticArray[SemanticInt.type], x) // error
 }

tests/pos/i23266.scala

@@ -0,0 +1,17 @@
+
+def kek(t: Table, ids: t.Id*) = ???
+
+trait Table {
+  type Id = String
+}
+
+object Table1 extends Table {
+  val id: Id = "table1_id"
+}
+
+class Table2() extends Table {
+  val id: Id = "table2_id"
+}
+
+val x = kek(Table1, Table1.id)
+val y = kek(Table2(), Table2().id)