diff options
Diffstat (limited to 'src/net/textproto/reader.go')
| -rw-r--r-- | src/net/textproto/reader.go | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/src/net/textproto/reader.go b/src/net/textproto/reader.go index 8e800088c1..48ae2946a6 100644 --- a/src/net/textproto/reader.go +++ b/src/net/textproto/reader.go @@ -489,8 +489,11 @@ func readMIMEHeader(r *Reader, lim int64) (MIMEHeader, error) { // large one ahead of time which we'll cut up into smaller // slices. If this isn't big enough later, we allocate small ones. var strs []string - hint := r.upcomingHeaderNewlines() + hint := r.upcomingHeaderKeys() if hint > 0 { + if hint > 1000 { + hint = 1000 // set a cap to avoid overallocation + } strs = make([]string, hint) } @@ -581,9 +584,9 @@ func mustHaveFieldNameColon(line []byte) error { var nl = []byte("\n") -// upcomingHeaderNewlines returns an approximation of the number of newlines +// upcomingHeaderKeys returns an approximation of the number of keys // that will be in this header. If it gets confused, it returns 0. -func (r *Reader) upcomingHeaderNewlines() (n int) { +func (r *Reader) upcomingHeaderKeys() (n int) { // Try to determine the 'hint' size. r.R.Peek(1) // force a buffer load if empty s := r.R.Buffered() @@ -591,7 +594,20 @@ func (r *Reader) upcomingHeaderNewlines() (n int) { return } peek, _ := r.R.Peek(s) - return bytes.Count(peek, nl) + for len(peek) > 0 && n < 1000 { + var line []byte + line, peek, _ = bytes.Cut(peek, nl) + if len(line) == 0 || (len(line) == 1 && line[0] == '\r') { + // Blank line separating headers from the body. + break + } + if line[0] == ' ' || line[0] == '\t' { + // Folded continuation of the previous line. + continue + } + n++ + } + return n } // CanonicalMIMEHeaderKey returns the canonical format of the |