fixes #23321; Error: internal error: openArrayLoc: ref array[0..0, int] (#23548)

fixes #23321

In the function `mapType`, ptrs (tyPtr, tyVar, tyLent, tyRef)
are mapped into ctPtrToArray, the dereference of which is skipped
in the `genref`. We need to skip these ptrs in the function
`genOpenArraySlice`.

compiler/ccgcalls.nim

@@ -166,7 +166,10 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
     genBoundsCheck(p, a, b, c)
   if prepareForMutation:
     linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
-  let ty = skipTypes(a.t, abstractVar+{tyPtr})
+  # bug #23321: In the function mapType, ptrs (tyPtr, tyVar, tyLent, tyRef)
+  # are mapped into ctPtrToArray, the dereference of which is skipped
+  # in the `genref`. We need to skip these ptrs here
+  let ty = skipTypes(a.t, abstractVar+{tyPtr, tyRef})
   let dest = getTypeDesc(p.module, destType)
   let lengthExpr = "($1)-($2)+1" % [rdLoc(c), rdLoc(b)]
   case ty.kind

tests/openarray/topenarray.nim

@@ -48,6 +48,41 @@ proc main =
       doAssert testing(mySeq) == mySeq
       doAssert testing(mySeq[2..^2]) == mySeq[2..^2]
 
+  block: # bug #23321
+    block:
+      proc foo(x: openArray[int]) =
+        doAssert x[0] == 0
+
+      var d = new array[1, int]
+      foo d[].toOpenArray(0, 0)
+
+    block:
+      proc foo(x: openArray[int]) =
+        doAssert x[0] == 0
+
+      proc task(x: var array[1, int]): var array[1, int] =
+        result = x
+      var d: array[1, int]
+      foo task(d).toOpenArray(0, 0)
+
+    block:
+      proc foo(x: openArray[int]) =
+        doAssert x[0] == 0
+
+      proc task(x: var array[1, int]): lent array[1, int] =
+        result = x
+      var d: array[1, int]
+      foo task(d).toOpenArray(0, 0)
+
+    block:
+      proc foo(x: openArray[int]) =
+        doAssert x[0] == 0
+
+      proc task(x: var array[1, int]): ptr array[1, int] =
+        result = addr x
+      var d: array[1, int]
+      foo task(d)[].toOpenArray(0, 0)
+
 
 main()
 static: main()