Merge pull request #427 from waschik/write-trunc

Write trunc

Author: yuin

iolib.go

@@ -629,7 +629,7 @@ func ioOpenFile(L *LState) int {
 		mode = os.O_RDONLY
 		writable = false
 	case "w", "wb":
-		mode = os.O_WRONLY | os.O_CREATE
+		mode = os.O_WRONLY | os.O_TRUNC | os.O_CREATE
 		readable = false
 	case "a", "ab":
 		mode = os.O_WRONLY | os.O_APPEND | os.O_CREATE

oslib_test.go

@@ -0,0 +1,33 @@
+package lua
+
+import (
+	"testing"
+)
+
+// correctly gc-ed. There was a bug in gopher lua where local vars were not being gc-ed in all circumstances.
+func TestOsWrite(t *testing.T) {
+	s := `
+		local function write(filename, content)
+		local f = assert(io.open(filename, "w"))
+		  f:write(content)
+		  assert(f:close())
+		end
+
+		local filename = os.tmpname()
+		write(filename, "abc")
+		write(filename, "d")
+		local f = assert(io.open(filename, "r"))
+		local content = f:read("*all"):gsub("%s+", "")
+		f:close()
+		os.remove(filename)
+		local expected = "d"
+		if content ~= expected then
+			error(string.format("Invalid content: Expecting \"%s\", got \"%s\"", expected, content))
+		end
+`
+	L := NewState()
+	defer L.Close()
+	if err := L.DoString(s); err != nil {
+		t.Error(err)
+	}
+}