bug fix

We were using the wrong scope variable for else-if statements. This was
only visible when no variables had been declared before the else-if.

gen/gen.go

@@ -461,13 +461,13 @@ func (v *visitor) finalizeNode() {
 
 			// Handle initializer, if it exists.
 			if ifstmt.Init != nil {
-				list = append(list, newCallStmt(idents.godebug, "ElseIfSimpleStmt", ast.NewIdent(idents.ctx), ast.NewIdent(idents.scope), newInt(pos2line(ifstmt.Init.Pos()))))
+				list = append(list, newCallStmt(idents.godebug, "ElseIfSimpleStmt", ast.NewIdent(idents.ctx), ast.NewIdent(v.scopeVar), newInt(pos2line(ifstmt.Init.Pos()))))
 				list = append(list, ifstmt.Init)
 				ifstmt.Init = nil
 			}
 
 			// Handle expression.
-			list = append(list, newCallStmt(idents.godebug, "ElseIfExpr", ast.NewIdent(idents.ctx), ast.NewIdent(idents.scope), newInt(pos2line(ifstmt.Cond.Pos()))))
+			list = append(list, newCallStmt(idents.godebug, "ElseIfExpr", ast.NewIdent(idents.ctx), ast.NewIdent(v.scopeVar), newInt(pos2line(ifstmt.Cond.Pos()))))
 			list = append(list, ifstmt)
 
 			// Swap in the new block.

testdata/regressions.yaml

@@ -26,3 +26,11 @@ invocations:
 creates:
     - $TMP/1.go
 transcript:
+---
+desc: else-if should work when no local variables have been declared
+invocations:
+    - dir: /
+      cmd: godebug run regressions/else-if.go
+creates:
+    - $TMP/else-if.go
+transcript:

testdata/test-filesystem/regressions/else-if.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"os"
+)
+
+func main() {
+	if o := os.Getenv("O"); o != "" {
+		println(o)
+	} else if s := os.Getenv("S"); s != "" {
+		println(s)
+	}
+}