code review 6212046: mime/multipart: fix handling of empty parts without CRL...

src/pkg/mime/multipart/multipart_test.go

 // Copyright 2010 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package multipart
 
 import (
         "bytes"
         "encoding/json"
         "fmt"
         "io"
         "io/ioutil"
+        "net/textproto"
         "os"
+        "reflect"
         "strings"
         "testing"
 )
-
-func TestHorizontalWhitespace(t *testing.T) {
-        if !onlyHorizontalWhitespace([]byte(" \t")) {
-                t.Error("expected pass")
-        }
-        if onlyHorizontalWhitespace([]byte("foo bar")) {
-                t.Error("expected failure")
-        }
-}
 
 func TestBoundaryLine(t *testing.T) {
         mr := NewReader(strings.NewReader(""), "myBoundary")
         if !mr.isBoundaryDelimiterLine([]byte("--myBoundary\r\n")) {
                 t.Error("expected")
         }
         if !mr.isBoundaryDelimiterLine([]byte("--myBoundary \r\n")) {
                 t.Error("expected")
         }
         if !mr.isBoundaryDelimiterLine([]byte("--myBoundary \n")) {
@@ skipping 276 matching lines @@
         part, err := r.NextPart()
         if err != nil {
                 t.Fatalf("didn't get a part")
         }
         _, err = io.Copy(ioutil.Discard, part)
         if err != io.ErrUnexpectedEOF {
                 t.Fatalf("expected error io.ErrUnexpectedEOF; got %v", err)
         }
 }
 
-func TestZeroLengthBody(t *testing.T) {
-        testBody := strings.Replace(`
-This is a multi-part message.  This line is ignored.
---MyBoundary
-foo: bar
-
-
---MyBoundary--
-`, "\n", "\r\n", -1)
-        r := NewReader(strings.NewReader(testBody), "MyBoundary")
-        part, err := r.NextPart()
-        if err != nil {
-                t.Fatalf("didn't get a part")
-        }
-        n, err := io.Copy(ioutil.Discard, part)
-        if err != nil {
-                t.Errorf("error reading part: %v", err)
-        }
-        if n != 0 {
-                t.Errorf("read %d bytes; expected 0", n)
-        }
-}
-
 type slowReader struct {
         r io.Reader
 }
 
 func (s *slowReader) Read(p []byte) (int, error) {
         if len(p) == 0 {
                 return s.r.Read(p)
         }
         return s.r.Read(p[:1])
 }
@@ skipping 65 matching lines @@
         _, err = mr.NextPart()
         if err != nil {
                 t.Fatalf("error reading the image attachment at the end: %v", err)
         }
 
         _, err = mr.NextPart()
         if err != io.EOF {
                 t.Fatalf("final outer NextPart = %v; want io.EOF", err)
         }
 }
+
+type headerBody struct {
+        header textproto.MIMEHeader
+        body   string
+}
+
+func formData(key, value string) headerBody {
+        return headerBody{
+                textproto.MIMEHeader{
+                        "Content-Type":        {"text/plain; charset=ISO-8859-1"},
+                        "Content-Disposition": {"form-data; name=" + key},
+                },
+                value,
+        }
+}
+
+type parseTest struct {
+        name    string
+        in, sep string
+        want    []headerBody
+}
+
+var parseTests = []parseTest{
+        // Actual body from App Engine on a blob upload. The final part (the
+        // Content-Type: message/external-body) is what App Engine replaces
+        // the uploaded file with.  The other form fields (prefixed with
+        // "other" in their form-data name) are unchanged.  A bug was
+        // reported with blob uploads failing when the other fields were
+        // empty. This was the MIME POST body that previously failed.
+        {
+                name: "App Engine post",
+                sep:  "00151757727e9583fd04bfbca4c6",
+                in:   "--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherEmpty1\r\n\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherFoo1\r\n\r\nfoo\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherFoo2\r\n\r\nfoo\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherEmpty2\r\n\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherRepeatFoo\r\n\r\nfoo\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherRepeatFoo\r\n\r\nfoo\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherRepeatEmpty\r\n\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=otherRepeatEmpty\r\n\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nContent-Disposition: form-data; name=submit\r\n\r\nSubmit\r\n--00151757727e9583fd04bfbca4c6\r\nContent-Type: message/external-body; charset=ISO-8859-1; blob-key=AHAZQqG84qllx7HUqO_oou5EvdYQNS3Mbbkb0RjjBoM_Kc1UqEN2ygDxWiyCPulIhpHRPx-VbpB6RX4MrsqhWAi_ZxJ48O9P2cTIACbvATHvg7IgbvZytyGMpL7xO1tlIvgwcM47JNfv_tGhy1XwyEUO8oldjPqg5Q\r\nContent-Disposition: form-data; name=file; filename=\"fall.png\"\r\n\r\nContent-Type: image/png\r\nContent-Length: 232303\r\nX-AppEngine-Upload-Creation: 2012-05-10 23:14:02.715173\r\nContent-MD5: MzRjODU1ZDZhZGU1NmRlOWEwZmMwMDdlODBmZTA0NzA=\r\nContent-Disposition: form-data; name=file; filename=\"fall.png\"\r\n\r\n\r\n--00151757727e9583fd04bfbca4c6--",
+                want: []headerBody{
+                        formData("otherEmpty1", ""),
+                        formData("otherFoo1", "foo"),
+                        formData("otherFoo2", "foo"),
+                        formData("otherEmpty2", ""),
+                        formData("otherRepeatFoo", "foo"),
+                        formData("otherRepeatFoo", "foo"),
+                        formData("otherRepeatEmpty", ""),
+                        formData("otherRepeatEmpty", ""),
+                        formData("submit", "Submit"),
+                        {textproto.MIMEHeader{
+                                "Content-Type":        {"message/external-body; charset=ISO-8859-1; blob-key=AHAZQqG84qllx7HUqO_oou5EvdYQNS3Mbbkb0RjjBoM_Kc1UqEN2ygDxWiyCPulIhpHRPx-VbpB6RX4MrsqhWAi_ZxJ48O9P2cTIACbvATHvg7IgbvZytyGMpL7xO1tlIvgwcM47JNfv_tGhy1XwyEUO8oldjPqg5Q"},
+                                "Content-Disposition": {"form-data; name=file; filename=\"fall.png\""},
+                        }, "Content-Type: image/png\r\nContent-Length: 232303\r\nX-AppEngine-Upload-Creation: 2012-05-10 23:14:02.715173\r\nContent-MD5: MzRjODU1ZDZhZGU1NmRlOWEwZmMwMDdlODBmZTA0NzA=\r\nContent-Disposition: form-data; name=file; filename=\"fall.png\"\r\n\r\n"},
+                },
+        },
+
+        // Single empty part, ended with --boundary immediately after headers.
+        {
+                name: "single empty part, --boundary",
+                sep:  "abc",
+                in:   "--abc\r\nFoo: bar\r\n\r\n--abc--",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                },
+        },
+
+        // Single empty part, ended with \r\n--boundary immediately after headers.
+        {
+                name: "single empty part, \r\n--boundary",
+                sep:  "abc",
+                in:   "--abc\r\nFoo: bar\r\n\r\n\r\n--abc--",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                },
+        },
+
+        // Final part empty.
+        {
+                name: "final part empty",
+                sep:  "abc",
+                in:   "--abc\r\nFoo: bar\r\n\r\n--abc\r\nFoo2: bar2\r\n\r\n--abc--",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                        {textproto.MIMEHeader{"Foo2": {"bar2"}}, ""},
+                },
+        },
+
+        // Final part empty with newlines after final separator.
+        {
+                name: "final part empty then crlf",
+                sep:  "abc",
+                in:   "--abc\r\nFoo: bar\r\n\r\n--abc--\r\n",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                },
+        },
+
+        // Final part empty with lwsp-chars after final separator.
+        {
+                name: "final part empty then lwsp",
+                sep:  "abc",
+                in:   "--abc\r\nFoo: bar\r\n\r\n--abc-- \t",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                },
+        },
+
+        // No parts (empty form as submitted by Chrome)
+        {
+                name: "no parts",
+                sep:  "----WebKitFormBoundaryQfEAfzFOiSemeHfA",
+                in:   "------WebKitFormBoundaryQfEAfzFOiSemeHfA--\r\n",
+                want: []headerBody{},
+        },
+
+        // Part containing data starting with the boundary, but with additional suffix.
+        {
+                name: "fake separator as data",
+                sep:  "sep",
+                in:   "--sep\r\nFoo: bar\r\n\r\n--sepFAKE\r\n--sep--",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, "--sepFAKE"},
+                },
+        },
+
+        // Part containing a boundary with whitespace following it.
+        {
+                name: "boundary with whitespace",
+                sep:  "sep",
+                in:   "--sep \r\nFoo: bar\r\n\r\ntext\r\n--sep--",
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, "text"},
+                },
+        },
+
+        // With ignored leading line.
+        {
+                name: "leading line",
+                sep:  "MyBoundary",
+                in: strings.Replace(`This is a multi-part message.  This line is ignored.
+--MyBoundary
+foo: bar
+
+
+--MyBoundary--`, "\n", "\r\n", -1),
+                want: []headerBody{
+                        {textproto.MIMEHeader{"Foo": {"bar"}}, ""},
+                },
+        },
+
+        roundTripParseTest(),
+}
+
+func TestParse(t *testing.T) {
+Cases:
+        for _, tt := range parseTests {
+                r := NewReader(strings.NewReader(tt.in), tt.sep)
+                got := []headerBody{}
+                for {
+                        p, err := r.NextPart()
+                        if err == io.EOF {
+                                break
+                        }
+                        if err != nil {
+                                t.Errorf("in test %q, NextPart: %v", tt.name, err)
+                                continue Cases
+                        }
+                        pbody, err := ioutil.ReadAll(p)
+                        if err != nil {
+                                t.Errorf("in test %q, error reading part: %v", tt.name, err)
+                                continue Cases
+                        }
+                        got = append(got, headerBody{p.Header, string(pbody)})
+                }
+                if !reflect.DeepEqual(tt.want, got) {
+                        t.Errorf("test %q:\n got: %v\nwant: %v", tt.name, got, tt.want)
+                        if len(tt.want) != len(got) {
+                                t.Errorf("test %q: got %d parts, want %d", tt.name, len(got), len(tt.want))
+                        } else if len(got) > 1 {
+                                for pi, wantPart := range tt.want {
+                                        if !reflect.DeepEqual(wantPart, got[pi]) {
+                                                t.Errorf("test %q, part %d:\n got: %v\nwant: %v", tt.name, pi, got[pi], wantPart)
+                                        }
+                                }
+                        }
+                }
+        }
+}
+
+func roundTripParseTest() parseTest {
+        t := parseTest{
+                name: "round trip",
+                want: []headerBody{
+                        formData("empty", ""),
+                        formData("lf", "\n"),
+                        formData("cr", "\r"),
+                        formData("crlf", "\r\n"),
+                        formData("foo", "bar"),
+                },
+        }
+        var buf bytes.Buffer
+        w := NewWriter(&buf)
+        for _, p := range t.want {
+                pw, err := w.CreatePart(p.header)
+                if err != nil {
+                        panic(err)
+                }
+                _, err = pw.Write([]byte(p.body))
+                if err != nil {
+                        panic(err)
+                }
+        }
+        w.Close()
+        t.in = buf.String()
+        t.sep = w.Boundary()
+        return t
+}