gopls/codeaction: fix panic when removing unused parameters with syntax errors.

Fixes golang/go#70268

Change-Id: I46643e79fc5cc30dac16bf18ef085bae173774a4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/626895
Reviewed-by: Robert Findley <[email protected]>
Reviewed-by: Sam Thanawalla <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Robert Findley <[email protected]>

Author: tttoad

gopls/internal/golang/inline_all.go

@@ -112,6 +112,7 @@ func inlineAllCalls(ctx context.Context, logf func(string, ...any), snapshot *ca
 		if err != nil {
 			return nil, bug.Errorf("finding %s in %s: %v", ref.URI, refpkg.Metadata().ID, err)
 		}
+
 		start, end, err := pgf.RangePos(ref.Range)
 		if err != nil {
 			return nil, err // e.g. invalid range
@@ -137,6 +138,20 @@ func inlineAllCalls(ctx context.Context, logf func(string, ...any), snapshot *ca
 			//    use(func(...) { f(...) })
 			return nil, fmt.Errorf("cannot inline: found non-call function reference %v", ref)
 		}
+
+		// Heuristic: ignore references that overlap with type checker errors, as they may
+		// lead to invalid results (see golang/go#70268).
+		hasTypeErrors := false
+		for _, typeErr := range refpkg.TypeErrors() {
+			if call.Lparen <= typeErr.Pos && typeErr.Pos <= call.Rparen {
+				hasTypeErrors = true
+			}
+		}
+
+		if hasTypeErrors {
+			continue
+		}
+
 		// Sanity check.
 		if obj := refpkg.TypesInfo().ObjectOf(name); obj == nil ||
 			obj.Name() != origDecl.Name.Name ||

gopls/internal/test/marker/testdata/codeaction/issue70268.txt

@@ -0,0 +1,33 @@
+This test verifies the remove of unused parameters in case of syntax errors.
+Issue golang/go#70268.
+
+-- go.mod --
+module unused.mod
+
+go 1.21
+
+-- a/a.go --
+package a
+
+func A(x, unused int) int { //@codeaction("unused", "unused", "refactor.rewrite.removeUnusedParam", a)
+	return x
+}
+
+-- b/b.go --
+package b
+
+import "unused.mod/a"
+
+func main(){
+	a.A/*dsdd*/(/*cccc*/ 1,
+
+
+	) //@diag(")", re"not enough arguments")
+}
+-- @a/a/a.go --
+package a
+
+func A(x int) int { //@codeaction("unused", "unused", "refactor.rewrite.removeUnusedParam", a)
+	return x
+}
+