1 files changed, 216 insertions, 0 deletions
diff --git a/src/mime/quotedprintable/reader_test.go b/src/mime/quotedprintable/reader_test.go
new file mode 100644
index 0000000..0af1e5f
--- /dev/null
+++ b/src/mime/quotedprintable/reader_test.go
@@ -0,0 +1,216 @@
+// Copyright 2012 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 quotedprintable
+
+import (
+	"bufio"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os/exec"
+	"regexp"
+	"sort"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestReader(t *testing.T) {
+	tests := []struct {
+		in, want string
+		err      any
+	}{
+		{in: "", want: ""},
+		{in: "foo bar", want: "foo bar"},
+		{in: "foo bar=3D", want: "foo bar="},
+		{in: "foo bar=3d", want: "foo bar="}, // lax.
+		{in: "foo bar=\n", want: "foo bar"},
+		{in: "foo bar\n", want: "foo bar\n"}, // somewhat lax.
+		{in: "foo bar=0", want: "foo bar=0"}, // lax
+		{in: "foo bar=0D=0A", want: "foo bar\r\n"},
+		{in: " A B        \r\n C ", want: " A B\r\n C"},
+		{in: " A B =\r\n C ", want: " A B  C"},
+		{in: " A B =\n C ", want: " A B  C"}, // lax. treating LF as CRLF
+		{in: "foo=\nbar", want: "foobar"},
+		{in: "foo\x00bar", want: "foo", err: "quotedprintable: invalid unescaped byte 0x00 in body"},
+		{in: "foo bar\xff", want: "foo bar\xff"},
+
+		// Equal sign.
+		{in: "=3D30\n", want: "=30\n"},
+		{in: "=00=FF0=\n", want: "\x00\xff0"},
+
+		// Trailing whitespace
+		{in: "foo  \n", want: "foo\n"},
+		{in: "foo  \n\nfoo =\n\nfoo=20\n\n", want: "foo\n\nfoo \nfoo \n\n"},
+
+		// Tests that we allow bare \n and \r through, despite it being strictly
+		// not permitted per RFC 2045, Section 6.7 Page 22 bullet (4).
+		{in: "foo\nbar", want: "foo\nbar"},
+		{in: "foo\rbar", want: "foo\rbar"},
+		{in: "foo\r\nbar", want: "foo\r\nbar"},
+
+		// Different types of soft line-breaks.
+		{in: "foo=\r\nbar", want: "foobar"},
+		{in: "foo=\nbar", want: "foobar"},
+		{in: "foo=\rbar", want: "foo", err: "quotedprintable: invalid hex byte 0x0d"},
+		{in: "foo=\r\r\r \nbar", want: "foo", err: `quotedprintable: invalid bytes after =: "\r\r\r \n"`},
+		// Issue 15486, accept trailing soft line-break at end of input.
+		{in: "foo=", want: "foo"},
+		{in: "=", want: "", err: `quotedprintable: invalid bytes after =: ""`},
+
+		// Example from RFC 2045:
+		{in: "Now's the time =\n" + "for all folk to come=\n" + " to the aid of their country.",
+			want: "Now's the time for all folk to come to the aid of their country."},
+		{in: "accept UTF-8 right quotation mark: ’",
+			want: "accept UTF-8 right quotation mark: ’"},
+	}
+	for _, tt := range tests {
+		var buf strings.Builder
+		_, err := io.Copy(&buf, NewReader(strings.NewReader(tt.in)))
+		if got := buf.String(); got != tt.want {
+			t.Errorf("for %q, got %q; want %q", tt.in, got, tt.want)
+		}
+		switch verr := tt.err.(type) {
+		case nil:
+			if err != nil {
+				t.Errorf("for %q, got unexpected error: %v", tt.in, err)
+			}
+		case string:
+			if got := fmt.Sprint(err); got != verr {
+				t.Errorf("for %q, got error %q; want %q", tt.in, got, verr)
+			}
+		case error:
+			if err != verr {
+				t.Errorf("for %q, got error %q; want %q", tt.in, err, verr)
+			}
+		}
+	}
+
+}
+
+func everySequence(base, alpha string, length int, fn func(string)) {
+	if len(base) == length {
+		fn(base)
+		return
+	}
+	for i := 0; i < len(alpha); i++ {
+		everySequence(base+alpha[i:i+1], alpha, length, fn)
+	}
+}
+
+var useQprint = flag.Bool("qprint", false, "Compare against the 'qprint' program.")
+
+var badSoftRx = regexp.MustCompile(`=([^\r\n]+?\n)|([^\r\n]+$)|(\r$)|(\r[^\n]+\n)|( \r\n)`)
+
+func TestExhaustive(t *testing.T) {
+	if *useQprint {
+		_, err := exec.LookPath("qprint")
+		if err != nil {
+			t.Fatalf("Error looking for qprint: %v", err)
+		}
+	}
+
+	var buf strings.Builder
+	res := make(map[string]int)
+	n := 6
+	if testing.Short() {
+		n = 4
+	}
+	everySequence("", "0A \r\n=", n, func(s string) {
+		if strings.HasSuffix(s, "=") || strings.Contains(s, "==") {
+			return
+		}
+		buf.Reset()
+		_, err := io.Copy(&buf, NewReader(strings.NewReader(s)))
+		if err != nil {
+			errStr := err.Error()
+			if strings.Contains(errStr, "invalid bytes after =:") {
+				errStr = "invalid bytes after ="
+			}
+			res[errStr]++
+			if strings.Contains(errStr, "invalid hex byte ") {
+				if strings.HasSuffix(errStr, "0x20") && (strings.Contains(s, "=0 ") || strings.Contains(s, "=A ") || strings.Contains(s, "= ")) {
+					return
+				}
+				if strings.HasSuffix(errStr, "0x3d") && (strings.Contains(s, "=0=") || strings.Contains(s, "=A=")) {
+					return
+				}
+				if strings.HasSuffix(errStr, "0x0a") || strings.HasSuffix(errStr, "0x0d") {
+					// bunch of cases; since whitespace at the end of a line before \n is removed.
+					return
+				}
+			}
+			if strings.Contains(errStr, "unexpected EOF") {
+				return
+			}
+			if errStr == "invalid bytes after =" && badSoftRx.MatchString(s) {
+				return
+			}
+			t.Errorf("decode(%q) = %v", s, err)
+			return
+		}
+		if *useQprint {
+			cmd := exec.Command("qprint", "-d")
+			cmd.Stdin = strings.NewReader(s)
+			stderr, err := cmd.StderrPipe()
+			if err != nil {
+				panic(err)
+			}
+			qpres := make(chan any, 2)
+			go func() {
+				br := bufio.NewReader(stderr)
+				s, _ := br.ReadString('\n')
+				if s != "" {
+					qpres <- errors.New(s)
+					if cmd.Process != nil {
+						// It can get stuck on invalid input, like:
+						// echo -n "0000= " | qprint -d
+						cmd.Process.Kill()
+					}
+				}
+			}()
+			go func() {
+				want, err := cmd.Output()
+				if err == nil {
+					qpres <- want
+				}
+			}()
+			select {
+			case got := <-qpres:
+				if want, ok := got.([]byte); ok {
+					if string(want) != buf.String() {
+						t.Errorf("go decode(%q) = %q; qprint = %q", s, want, buf.String())
+					}
+				} else {
+					t.Logf("qprint -d(%q) = %v", s, got)
+				}
+			case <-time.After(5 * time.Second):
+				t.Logf("qprint timeout on %q", s)
+			}
+		}
+		res["OK"]++
+	})
+	var outcomes []string
+	for k, v := range res {
+		outcomes = append(outcomes, fmt.Sprintf("%v: %d", k, v))
+	}
+	sort.Strings(outcomes)
+	got := strings.Join(outcomes, "\n")
+	want := `OK: 28934
+invalid bytes after =: 3949
+quotedprintable: invalid hex byte 0x0d: 2048
+unexpected EOF: 194`
+	if testing.Short() {
+		want = `OK: 896
+invalid bytes after =: 100
+quotedprintable: invalid hex byte 0x0d: 26
+unexpected EOF: 3`
+	}
+
+	if got != want {
+		t.Errorf("Got:\n%s\nWant:\n%s", got, want)
+	}
+}