/
patch.go
64 lines (59 loc) · 1.54 KB
/
patch.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
// Copyright 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
package email
import (
"bufio"
"bytes"
"regexp"
"strings"
)
func ParsePatch(message []byte) (diff string) {
s := bufio.NewScanner(bytes.NewReader(message))
diffStarted := false
for s.Scan() {
ln := s.Text()
if lineMatchesDiffStart(ln) {
diffStarted = true
diff += ln + "\n"
continue
}
if diffStarted {
if ln == "" || ln == "--" || ln == "-- " || ln[0] == '>' {
diffStarted = false
continue
}
if strings.HasPrefix(ln, " ") || strings.HasPrefix(ln, "+") ||
strings.HasPrefix(ln, "-") || strings.HasPrefix(ln, "@") ||
strings.HasPrefix(ln, "================") {
diff += ln + "\n"
continue
}
}
}
err := s.Err()
if err == bufio.ErrTooLong {
// It's a problem of the incoming patch, rather than anything else.
// Anyway, if a patch contains too long lines, we're probably not
// interested in it, so let's pretent we didn't see it.
diff = ""
return
} else if err != nil {
panic("error while scanning from memory: " + err.Error())
}
return
}
var diffRegexps = []*regexp.Regexp{
regexp.MustCompile(`^(---|\+\+\+) [^\s]`),
regexp.MustCompile(`^diff --git`),
regexp.MustCompile(`^index [0-9a-f]+\.\.[0-9a-f]+`),
regexp.MustCompile(`^new file mode [0-9]+`),
regexp.MustCompile(`^Index: [^\s]`),
}
func lineMatchesDiffStart(ln string) bool {
for _, re := range diffRegexps {
if re.MatchString(ln) {
return true
}
}
return false
}