Update deps

vendor/github.com/sourcegraph/go-diff/LICENSE

@@ -0,0 +1,35 @@
+Copyright (c) 2014 Sourcegraph, Inc.
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+-----------------------------------------------------------------
+
+Portions adapted from python-unidiff:
+
+Copyright (c) 2012 Matias Bordese
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:

vendor/github.com/sourcegraph/go-diff/diff/diff.go

@@ -0,0 +1,132 @@
+package diff
+
+import (
+	"bytes"
+	"time"
+)
+
+// A FileDiff represents a unified diff for a single file.
+//
+// A file unified diff has a header that resembles the following:
+//
+//   --- oldname	2009-10-11 15:12:20.000000000 -0700
+//   +++ newname	2009-10-11 15:12:30.000000000 -0700
+type FileDiff struct {
+	// the original name of the file
+	OrigName string
+	// the original timestamp (nil if not present)
+	OrigTime *time.Time
+	// the new name of the file (often same as OrigName)
+	NewName string
+	// the new timestamp (nil if not present)
+	NewTime *time.Time
+	// extended header lines (e.g., git's "new mode <mode>", "rename from <path>", etc.)
+	Extended []string
+	// hunks that were changed from orig to new
+	Hunks []*Hunk
+}
+
+// A Hunk represents a series of changes (additions or deletions) in a file's
+// unified diff.
+type Hunk struct {
+	// starting line number in original file
+	OrigStartLine int32
+	// number of lines the hunk applies to in the original file
+	OrigLines int32
+	// if > 0, then the original file had a 'No newline at end of file' mark at this offset
+	OrigNoNewlineAt int32
+	// starting line number in new file
+	NewStartLine int32
+	// number of lines the hunk applies to in the new file
+	NewLines int32
+	// optional section heading
+	Section string
+	// 0-indexed line offset in unified file diff (including section headers); this is
+	// only set when Hunks are read from entire file diff (i.e., when ReadAllHunks is
+	// called) This accounts for hunk headers, too, so the StartPosition of the first
+	// hunk will be 1.
+	StartPosition int32
+	// hunk body (lines prefixed with '-', '+', or ' ')
+	Body []byte
+}
+
+// A Stat is a diff stat that represents the number of lines added/changed/deleted.
+type Stat struct {
+	// number of lines added
+	Added int32
+	// number of lines changed
+	Changed int32
+	// number of lines deleted
+	Deleted int32
+}
+
+// Stat computes the number of lines added/changed/deleted in all
+// hunks in this file's diff.
+func (d *FileDiff) Stat() Stat {
+	total := Stat{}
+	for _, h := range d.Hunks {
+		total.add(h.Stat())
+	}
+	return total
+}
+
+// Stat computes the number of lines added/changed/deleted in this
+// hunk.
+func (h *Hunk) Stat() Stat {
+	lines := bytes.Split(h.Body, []byte{'\n'})
+	var last byte
+	st := Stat{}
+	for _, line := range lines {
+		if len(line) == 0 {
+			last = 0
+			continue
+		}
+		switch line[0] {
+		case '-':
+			if last == '+' {
+				st.Added--
+				st.Changed++
+				last = 0 // next line can't change this one since this is already a change
+			} else {
+				st.Deleted++
+				last = line[0]
+			}
+		case '+':
+			if last == '-' {
+				st.Deleted--
+				st.Changed++
+				last = 0 // next line can't change this one since this is already a change
+			} else {
+				st.Added++
+				last = line[0]
+			}
+		default:
+			last = 0
+		}
+	}
+	return st
+}
+
+var (
+	hunkPrefix          = []byte("@@ ")
+	onlyInMessagePrefix = []byte("Only in ")
+)
+
+const hunkHeader = "@@ -%d,%d +%d,%d @@"
+const onlyInMessage = "Only in %s: %s\n"
+
+// diffTimeParseLayout is the layout used to parse the time in unified diff file
+// header timestamps.
+// See https://www.gnu.org/software/diffutils/manual/html_node/Detailed-Unified.html.
+const diffTimeParseLayout = "2006-01-02 15:04:05 -0700"
+
+// diffTimeFormatLayout is the layout used to format (i.e., print) the time in unified diff file
+// header timestamps.
+// See https://www.gnu.org/software/diffutils/manual/html_node/Detailed-Unified.html.
+const diffTimeFormatLayout = "2006-01-02 15:04:05.000000000 -0700"
+
+func (s *Stat) add(o Stat) {
+	s.Added += o.Added
+	s.Changed += o.Changed
+	s.Deleted += o.Deleted
+}

vendor/github.com/sourcegraph/go-diff/diff/doc.go

@@ -0,0 +1,2 @@
+// Package diff provides a parser for unified diffs.
+package diff

vendor/github.com/sourcegraph/go-diff/diff/parse.go

@@ -0,0 +1,725 @@
+package diff
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ParseMultiFileDiff parses a multi-file unified diff. It returns an error if
+// parsing failed as a whole, but does its best to parse as many files in the
+// case of per-file errors. If it cannot detect when the diff of the next file
+// begins, the hunks are added to the FileDiff of the previous file.
+func ParseMultiFileDiff(diff []byte) ([]*FileDiff, error) {
+	return NewMultiFileDiffReader(bytes.NewReader(diff)).ReadAllFiles()
+}
+
+// NewMultiFileDiffReader returns a new MultiFileDiffReader that reads
+// a multi-file unified diff from r.
+func NewMultiFileDiffReader(r io.Reader) *MultiFileDiffReader {
+	return &MultiFileDiffReader{reader: bufio.NewReader(r)}
+}
+
+// MultiFileDiffReader reads a multi-file unified diff.
+type MultiFileDiffReader struct {
+	line   int
+	offset int64
+	reader *bufio.Reader
+
+	// TODO(sqs): line and offset tracking in multi-file diffs is broken; add tests and fix
+
+	// nextFileFirstLine is a line that was read by a HunksReader that
+	// was how it determined the hunk was complete. But to determine
+	// that, it needed to read the first line of the next file. We
+	// store nextFileFirstLine so we can "give the first line back" to
+	// the next file.
+	nextFileFirstLine []byte
+}
+
+// ReadFile reads the next file unified diff (including headers and
+// all hunks) from r. If there are no more files in the diff, it
+// returns error io.EOF.
+func (r *MultiFileDiffReader) ReadFile() (*FileDiff, error) {
+	fr := &FileDiffReader{
+		line:           r.line,
+		offset:         r.offset,
+		reader:         r.reader,
+		fileHeaderLine: r.nextFileFirstLine,
+	}
+	r.nextFileFirstLine = nil
+
+	fd, err := fr.ReadAllHeaders()
+	if err != nil {
+		switch e := err.(type) {
+		case *ParseError:
+			if e.Err == ErrNoFileHeader || e.Err == ErrExtendedHeadersEOF {
+				return nil, io.EOF
+			}
+			return nil, err
+
+		case OverflowError:
+			r.nextFileFirstLine = []byte(e)
+			return fd, nil
+
+		default:
+			return nil, err
+		}
+	}
+
+	// FileDiff is added/deleted file
+	// No further collection of hunks needed
+	if fd.NewName == "" {
+		return fd, nil
+	}
+
+	// Before reading hunks, check to see if there are any. If there
+	// aren't any, and there's another file after this file in the
+	// diff, then the hunks reader will complain ErrNoHunkHeader. It's
+	// not easy for us to tell from that error alone if that was
+	// caused by the lack of any hunks, or a malformatted hunk, so we
+	// need to perform the check here.
+	hr := fr.HunksReader()
+	line, err := readLine(r.reader)
+	if err != nil && err != io.EOF {
+		return fd, err
+	}
+	line = bytes.TrimSuffix(line, []byte{'\n'})
+	if bytes.HasPrefix(line, hunkPrefix) {
+		hr.nextHunkHeaderLine = line
+		fd.Hunks, err = hr.ReadAllHunks()
+		r.line = fr.line
+		r.offset = fr.offset
+		if err != nil {
+			if e0, ok := err.(*ParseError); ok {
+				if e, ok := e0.Err.(*ErrBadHunkLine); ok {
+					// This just means we finished reading the hunks for the
+					// current file. See the ErrBadHunkLine doc for more info.
+					r.nextFileFirstLine = e.Line
+					return fd, nil
+				}
+			}
+			return nil, err
+		}
+	} else {
+		// There weren't any hunks, so that line we peeked ahead at
+		// actually belongs to the next file. Put it back.
+		r.nextFileFirstLine = line
+	}
+
+	return fd, nil
+}
+
+// ReadAllFiles reads all file unified diffs (including headers and all
+// hunks) remaining in r.
+func (r *MultiFileDiffReader) ReadAllFiles() ([]*FileDiff, error) {
+	var ds []*FileDiff
+	for {
+		d, err := r.ReadFile()
+		if d != nil {
+			ds = append(ds, d)
+		}
+		if err == io.EOF {
+			return ds, nil
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
+}
+
+// ParseFileDiff parses a file unified diff.
+func ParseFileDiff(diff []byte) (*FileDiff, error) {
+	return NewFileDiffReader(bytes.NewReader(diff)).Read()
+}
+
+// NewFileDiffReader returns a new FileDiffReader that reads a file
+// unified diff.
+func NewFileDiffReader(r io.Reader) *FileDiffReader {
+	return &FileDiffReader{reader: bufio.NewReader(r)}
+}
+
+// FileDiffReader reads a unified file diff.
+type FileDiffReader struct {
+	line   int
+	offset int64
+	reader *bufio.Reader
+
+	// fileHeaderLine is the first file header line, set by:
+	//
+	// (1) ReadExtendedHeaders if it encroaches on a file header line
+	//     (which it must to detect when extended headers are done); or
+	// (2) (*MultiFileDiffReader).ReadFile() if it encroaches on a
+	//     file header line while reading the previous file's hunks (in a
+	//     multi-file diff).
+	fileHeaderLine []byte
+}
+
+// Read reads a file unified diff, including headers and hunks, from r.
+func (r *FileDiffReader) Read() (*FileDiff, error) {
+	fd, err := r.ReadAllHeaders()
+	if err != nil {
+		return nil, err
+	}
+
+	fd.Hunks, err = r.HunksReader().ReadAllHunks()
+	if err != nil {
+		return nil, err
+	}
+
+	return fd, nil
+}
+
+// ReadAllHeaders reads the file headers and extended headers (if any)
+// from a file unified diff. It does not read hunks, and the returned
+// FileDiff's Hunks field is nil. To read the hunks, call the
+// (*FileDiffReader).HunksReader() method to get a HunksReader and
+// read hunks from that.
+func (r *FileDiffReader) ReadAllHeaders() (*FileDiff, error) {
+	var err error
+	fd := &FileDiff{}
+
+	fd.Extended, err = r.ReadExtendedHeaders()
+	if pe, ok := err.(*ParseError); ok && pe.Err == ErrExtendedHeadersEOF {
+		wasEmpty := handleEmpty(fd)
+		if wasEmpty {
+			return fd, nil
+		}
+		return fd, err
+	} else if _, ok := err.(OverflowError); ok {
+		handleEmpty(fd)
+		return fd, err
+	} else if err != nil {
+		return fd, err
+	}
+
+	var origTime, newTime *time.Time
+	fd.OrigName, fd.NewName, origTime, newTime, err = r.ReadFileHeaders()
+	if err != nil {
+		return nil, err
+	}
+	if origTime != nil {
+		fd.OrigTime = origTime
+	}
+	if newTime != nil {
+		fd.NewTime = newTime
+	}
+
+	return fd, nil
+}
+
+// HunksReader returns a new HunksReader that reads hunks from r. The
+// HunksReader's line and offset (used in error messages) is set to
+// start where the file diff header ended (which means errors have the
+// correct position information).
+func (r *FileDiffReader) HunksReader() *HunksReader {
+	return &HunksReader{
+		line:   r.line,
+		offset: r.offset,
+		reader: r.reader,
+	}
+}
+
+// ReadFileHeaders reads the unified file diff header (the lines that
+// start with "---" and "+++" with the orig/new file names and
+// timestamps). Or which starts with "Only in " with dir path and filename.
+// "Only in" message is supported in POSIX locale: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/diff.html#tag_20_34_10
+func (r *FileDiffReader) ReadFileHeaders() (origName, newName string, origTimestamp, newTimestamp *time.Time, err error) {
+	if r.fileHeaderLine != nil {
+		if isOnlyMessage, source, filename := parseOnlyInMessage(r.fileHeaderLine); isOnlyMessage {
+			return filepath.Join(string(source), string(filename)),
+				"", nil, nil, nil
+		}
+	}
+
+	origName, origTimestamp, err = r.readOneFileHeader([]byte("--- "))
+	if err != nil {
+		return "", "", nil, nil, err
+	}
+
+	newName, newTimestamp, err = r.readOneFileHeader([]byte("+++ "))
+	if err != nil {
+		return "", "", nil, nil, err
+	}
+
+	unquotedOrigName, err := strconv.Unquote(origName)
+	if err == nil {
+		origName = unquotedOrigName
+	}
+	unquotedNewName, err := strconv.Unquote(newName)
+	if err == nil {
+		newName = unquotedNewName
+	}
+
+	return origName, newName, origTimestamp, newTimestamp, nil
+}
+
+// readOneFileHeader reads one of the file headers (prefix should be
+// either "+++ " or "--- ").
+func (r *FileDiffReader) readOneFileHeader(prefix []byte) (filename string, timestamp *time.Time, err error) {
+	var line []byte
+
+	if r.fileHeaderLine == nil {
+		var err error
+		line, err = readLine(r.reader)
+		if err == io.EOF {
+			return "", nil, &ParseError{r.line, r.offset, ErrNoFileHeader}
+		} else if err != nil {
+			return "", nil, err
+		}
+	} else {
+		line = r.fileHeaderLine
+		r.fileHeaderLine = nil
+	}
+
+	if !bytes.HasPrefix(line, prefix) {
+		return "", nil, &ParseError{r.line, r.offset, ErrBadFileHeader}
+	}
+
+	r.offset += int64(len(line))
+	r.line++
+	line = line[len(prefix):]
+
+	trimmedLine := strings.TrimSpace(string(line)) // filenames that contain spaces may be terminated by a tab
+	parts := strings.SplitN(trimmedLine, "\t", 2)
+	filename = parts[0]
+	if len(parts) == 2 {
+		// Timestamp is optional, but this header has it.
+		ts, err := time.Parse(diffTimeParseLayout, parts[1])
+		if err != nil {
+			return "", nil, err
+		}
+		timestamp = &ts
+	}
+
+	return filename, timestamp, err
+}
+
+// OverflowError is returned when we have overflowed into the start
+// of the next file while reading extended headers.
+type OverflowError string
+
+func (e OverflowError) Error() string {
+	return fmt.Sprintf("overflowed into next file: %s", string(e))
+}
+
+// ReadExtendedHeaders reads the extended header lines, if any, from a
+// unified diff file (e.g., git's "diff --git a/foo.go b/foo.go", "new
+// mode <mode>", "rename from <path>", etc.).
+func (r *FileDiffReader) ReadExtendedHeaders() ([]string, error) {
+	var xheaders []string
+	firstLine := true
+	for {
+		var line []byte
+		if r.fileHeaderLine == nil {
+			var err error
+			line, err = readLine(r.reader)
+			if err == io.EOF {
+				return xheaders, &ParseError{r.line, r.offset, ErrExtendedHeadersEOF}
+			} else if err != nil {
+				return xheaders, err
+			}
+		} else {
+			line = r.fileHeaderLine
+			r.fileHeaderLine = nil
+		}
+
+		if bytes.HasPrefix(line, []byte("diff --git ")) {
+			if firstLine {
+				firstLine = false
+			} else {
+				return xheaders, OverflowError(line)
+			}
+		}
+		if bytes.HasPrefix(line, []byte("--- ")) {
+			// We've reached the file header.
+			r.fileHeaderLine = line // pass to readOneFileHeader (see fileHeaderLine field doc)
+			return xheaders, nil
+		}
+
+		// Reached message that file is added/deleted
+		if isOnlyInMessage, _, _ := parseOnlyInMessage(line); isOnlyInMessage {
+			r.fileHeaderLine = line // pass to readOneFileHeader (see fileHeaderLine field doc)
+			return xheaders, nil
+		}
+
+		r.line++
+		r.offset += int64(len(line))
+		xheaders = append(xheaders, string(line))
+	}
+}
+
+// handleEmpty detects when FileDiff was an empty diff and will not have any hunks
+// that follow. It updates fd fields from the parsed extended headers.
+func handleEmpty(fd *FileDiff) (wasEmpty bool) {
+	var err error
+	lineCount := len(fd.Extended)
+	if lineCount > 0 && !strings.HasPrefix(fd.Extended[0], "diff --git ") {
+		return false
+	}
+	switch {
+	case (lineCount == 3 || lineCount == 4 && strings.HasPrefix(fd.Extended[3], "Binary files ") || lineCount > 4 && strings.HasPrefix(fd.Extended[3], "GIT binary patch")) &&
+		strings.HasPrefix(fd.Extended[1], "new file mode "):
+
+		names := strings.SplitN(fd.Extended[0][len("diff --git "):], " ", 2)
+		fd.OrigName = "/dev/null"
+		fd.NewName, err = strconv.Unquote(names[1])
+		if err != nil {
+			fd.NewName = names[1]
+		}
+		return true
+	case (lineCount == 3 || lineCount == 4 && strings.HasPrefix(fd.Extended[3], "Binary files ") || lineCount > 4 && strings.HasPrefix(fd.Extended[3], "GIT binary patch")) &&
+		strings.HasPrefix(fd.Extended[1], "deleted file mode "):
+
+		names := strings.SplitN(fd.Extended[0][len("diff --git "):], " ", 2)
+		fd.OrigName, err = strconv.Unquote(names[0])
+		if err != nil {
+			fd.OrigName = names[0]
+		}
+		fd.NewName = "/dev/null"
+		return true
+	case lineCount == 4 && strings.HasPrefix(fd.Extended[2], "rename from ") && strings.HasPrefix(fd.Extended[3], "rename to "):
+		names := strings.SplitN(fd.Extended[0][len("diff --git "):], " ", 2)
+		fd.OrigName, err = strconv.Unquote(names[0])
+		if err != nil {
+			fd.OrigName = names[0]
+		}
+		fd.NewName, err = strconv.Unquote(names[1])
+		if err != nil {
+			fd.NewName = names[1]
+		}
+		return true
+	case lineCount == 6 && strings.HasPrefix(fd.Extended[5], "Binary files ") && strings.HasPrefix(fd.Extended[2], "rename from ") && strings.HasPrefix(fd.Extended[3], "rename to "):
+		names := strings.SplitN(fd.Extended[0][len("diff --git "):], " ", 2)
+		fd.OrigName = names[0]
+		fd.NewName = names[1]
+		return true
+	case lineCount == 3 && strings.HasPrefix(fd.Extended[2], "Binary files ") || lineCount > 3 && strings.HasPrefix(fd.Extended[2], "GIT binary patch"):
+		names := strings.SplitN(fd.Extended[0][len("diff --git "):], " ", 2)
+		fd.OrigName, err = strconv.Unquote(names[0])
+		if err != nil {
+			fd.OrigName = names[0]
+		}
+		fd.NewName, err = strconv.Unquote(names[1])
+		if err != nil {
+			fd.NewName = names[1]
+		}
+		return true
+	default:
+		return false
+	}
+}
+
+var (
+	// ErrNoFileHeader is when a file unified diff has no file header
+	// (i.e., the lines that begin with "---" and "+++").
+	ErrNoFileHeader = errors.New("expected file header, got EOF")
+
+	// ErrBadFileHeader is when a file unified diff has a malformed
+	// file header (i.e., the lines that begin with "---" and "+++").
+	ErrBadFileHeader = errors.New("bad file header")
+
+	// ErrExtendedHeadersEOF is when an EOF was encountered while reading extended file headers, which means that there were no ---/+++ headers encountered before hunks (if any) began.
+	ErrExtendedHeadersEOF = errors.New("expected file header while reading extended headers, got EOF")
+
+	// ErrBadOnlyInMessage is when a file have a malformed `only in` message
+	// Should be in format `Only in {source}: {filename}`
+	ErrBadOnlyInMessage = errors.New("bad 'only in' message")
+)
+
+// ParseHunks parses hunks from a unified diff. The diff must consist
+// only of hunks and not include a file header; if it has a file
+// header, use ParseFileDiff.
+func ParseHunks(diff []byte) ([]*Hunk, error) {
+	r := NewHunksReader(bytes.NewReader(diff))
+	hunks, err := r.ReadAllHunks()
+	if err != nil {
+		return nil, err
+	}
+	return hunks, nil
+}
+
+// NewHunksReader returns a new HunksReader that reads unified diff hunks
+// from r.
+func NewHunksReader(r io.Reader) *HunksReader {
+	return &HunksReader{reader: bufio.NewReader(r)}
+}
+
+// A HunksReader reads hunks from a unified diff.
+type HunksReader struct {
+	line   int
+	offset int64
+	hunk   *Hunk
+	reader *bufio.Reader
+
+	nextHunkHeaderLine []byte
+}
+
+// ReadHunk reads one hunk from r. If there are no more hunks, it
+// returns error io.EOF.
+func (r *HunksReader) ReadHunk() (*Hunk, error) {
+	r.hunk = nil
+	lastLineFromOrig := true
+	var line []byte
+	var err error
+	for {
+		if r.nextHunkHeaderLine != nil {
+			// Use stored hunk header line that was scanned in at the
+			// completion of the previous hunk's ReadHunk.
+			line = r.nextHunkHeaderLine
+			r.nextHunkHeaderLine = nil
+		} else {
+			line, err = readLine(r.reader)
+			if err != nil {
+				if err == io.EOF && r.hunk != nil {
+					return r.hunk, nil
+				}
+				return nil, err
+			}
+		}
+
+		// Record position.
+		r.line++
+		r.offset += int64(len(line))
+
+		if r.hunk == nil {
+			// Check for presence of hunk header.
+			if !bytes.HasPrefix(line, hunkPrefix) {
+				return nil, &ParseError{r.line, r.offset, ErrNoHunkHeader}
+			}
+
+			// Parse hunk header.
+			r.hunk = &Hunk{}
+			items := []interface{}{
+				&r.hunk.OrigStartLine, &r.hunk.OrigLines,
+				&r.hunk.NewStartLine, &r.hunk.NewLines,
+			}
+			header, section, err := normalizeHeader(string(line))
+			if err != nil {
+				return nil, &ParseError{r.line, r.offset, err}
+			}
+			n, err := fmt.Sscanf(header, hunkHeader, items...)
+			if err != nil {
+				return nil, err
+			}
+			if n < len(items) {
+				return nil, &ParseError{r.line, r.offset, &ErrBadHunkHeader{header: string(line)}}
+			}
+
+			r.hunk.Section = section
+		} else {
+			// Read hunk body line.
+
+			// If the line starts with `---` and the next one with `+++` we're
+			// looking at a non-extended file header and need to abort.
+			if bytes.HasPrefix(line, []byte("---")) {
+				ok, err := peekPrefix(r.reader, "+++")
+				if err != nil {
+					return r.hunk, err
+				}
+				if ok {
+					return r.hunk, &ParseError{r.line, r.offset, &ErrBadHunkLine{Line: line}}
+				}
+			}
+
+			// If the line starts with the hunk prefix, this hunk is complete.
+			if bytes.HasPrefix(line, hunkPrefix) {
+				// But we've already read in the next hunk's
+				// header, so we need to be sure that the next call to
+				// ReadHunk starts with that header.
+				r.nextHunkHeaderLine = line
+
+				// Rewind position.
+				r.line--
+				r.offset -= int64(len(line))
+
+				return r.hunk, nil
+			}
+
+			if len(line) >= 1 && !linePrefix(line[0]) {
+				// Bad hunk header line. If we're reading a multi-file
+				// diff, this may be the end of the current
+				// file. Return a "rich" error that lets our caller
+				// handle that case.
+				return r.hunk, &ParseError{r.line, r.offset, &ErrBadHunkLine{Line: line}}
+			}
+			if bytes.Equal(line, []byte(noNewlineMessage)) {
+				if lastLineFromOrig {
+					// Retain the newline in the body (otherwise the
+					// diff line would be like "-a+b", where "+b" is
+					// the the next line of the new file, which is not
+					// validly formatted) but record that the orig had
+					// no newline.
+					r.hunk.OrigNoNewlineAt = int32(len(r.hunk.Body))
+				} else {
+					// Remove previous line's newline.
+					if len(r.hunk.Body) != 0 {
+						r.hunk.Body = r.hunk.Body[:len(r.hunk.Body)-1]
+					}
+				}
+				continue
+			}
+
+			if len(line) > 0 {
+				lastLineFromOrig = line[0] == '-'
+			}
+
+			r.hunk.Body = append(r.hunk.Body, line...)
+			r.hunk.Body = append(r.hunk.Body, '\n')
+		}
+	}
+}
+
+const noNewlineMessage = `\ No newline at end of file`
+
+// linePrefixes is the set of all characters a valid line in a diff
+// hunk can start with. '\' can appear in diffs when no newline is
+// present at the end of a file.
+// See: 'http://www.gnu.org/software/diffutils/manual/diffutils.html#Incomplete-Lines'
+var linePrefixes = []byte{' ', '-', '+', '\\'}
+
+// linePrefix returns true if 'c' is in 'linePrefixes'.
+func linePrefix(c byte) bool {
+	for _, p := range linePrefixes {
+		if p == c {
+			return true
+		}
+	}
+	return false
+}
+
+// peekPrefix peeks into the given reader to check whether the next
+// bytes match the given prefix.
+func peekPrefix(reader *bufio.Reader, prefix string) (bool, error) {
+	next, err := reader.Peek(len(prefix))
+	if err != nil {
+		if err == io.EOF {
+			return false, nil
+		}
+		return false, err
+	}
+	return bytes.HasPrefix(next, []byte(prefix)), nil
+}
+
+// normalizeHeader takes a header of the form:
+// "@@ -linestart[,chunksize] +linestart[,chunksize] @@ section"
+// and returns two strings, with the first in the form:
+// "@@ -linestart,chunksize +linestart,chunksize @@".
+// where linestart and chunksize are both integers. The second is the
+// optional section header. chunksize may be omitted from the header
+// if its value is 1. normalizeHeader returns an error if the header
+// is not in the correct format.
+func normalizeHeader(header string) (string, string, error) {
+	// Split the header into five parts: the first '@@', the two
+	// ranges, the last '@@', and the optional section.
+	pieces := strings.SplitN(header, " ", 5)
+	if len(pieces) < 4 {
+		return "", "", &ErrBadHunkHeader{header: header}
+	}
+
+	if pieces[0] != "@@" {
+		return "", "", &ErrBadHunkHeader{header: header}
+	}
+	for i := 1; i < 3; i++ {
+		if !strings.ContainsRune(pieces[i], ',') {
+			pieces[i] = pieces[i] + ",1"
+		}
+	}
+	if pieces[3] != "@@" {
+		return "", "", &ErrBadHunkHeader{header: header}
+	}
+
+	var section string
+	if len(pieces) == 5 {
+		section = pieces[4]
+	}
+	return strings.Join(pieces, " "), strings.TrimSpace(section), nil
+}
+
+// ReadAllHunks reads all remaining hunks from r. A successful call
+// returns err == nil, not err == EOF. Because ReadAllHunks is defined
+// to read until EOF, it does not treat end of file as an error to be
+// reported.
+func (r *HunksReader) ReadAllHunks() ([]*Hunk, error) {
+	var hunks []*Hunk
+	linesRead := int32(0)
+	for {
+		hunk, err := r.ReadHunk()
+		if err == io.EOF {
+			return hunks, nil
+		}
+		if hunk != nil {
+			linesRead++ // account for the hunk header line
+			hunk.StartPosition = linesRead
+			hunks = append(hunks, hunk)
+			linesRead += int32(bytes.Count(hunk.Body, []byte{'\n'}))
+		}
+		if err != nil {
+			return hunks, err
+		}
+	}
+}
+
+// parseOnlyInMessage checks if line is a "Only in {source}: {filename}" and returns source and filename
+func parseOnlyInMessage(line []byte) (bool, []byte, []byte) {
+	if !bytes.HasPrefix(line, onlyInMessagePrefix) {
+		return false, nil, nil
+	}
+	line = line[len(onlyInMessagePrefix):]
+	idx := bytes.Index(line, []byte(": "))
+	if idx < 0 {
+		return false, nil, nil
+	}
+	return true, line[:idx], line[idx+2:]
+}
+
+// A ParseError is a description of a unified diff syntax error.
+type ParseError struct {
+	Line   int   // Line where the error occurred
+	Offset int64 // Offset where the error occurred
+	Err    error // The actual error
+}
+
+func (e *ParseError) Error() string {
+	return fmt.Sprintf("line %d, char %d: %s", e.Line, e.Offset, e.Err)
+}
+
+// ErrNoHunkHeader indicates that a unified diff hunk header was
+// expected but not found during parsing.
+var ErrNoHunkHeader = errors.New("no hunk header")
+
+// ErrBadHunkHeader indicates that a malformed unified diff hunk
+// header was encountered during parsing.
+type ErrBadHunkHeader struct {
+	header string
+}
+
+func (e *ErrBadHunkHeader) Error() string {
+	if e.header == "" {
+		return "bad hunk header"
+	}
+	return "bad hunk header: " + e.header
+}
+
+// ErrBadHunkLine is when a line not beginning with ' ', '-', '+', or
+// '\' is encountered while reading a hunk. In the context of reading
+// a single hunk or file, it is an unexpected error. In a multi-file
+// diff, however, it indicates that the current file's diff is
+// complete (and remaining diff data will describe another file
+// unified diff).
+type ErrBadHunkLine struct {
+	Line []byte
+}
+
+func (e *ErrBadHunkLine) Error() string {
+	m := "bad hunk line (does not start with ' ', '-', '+', or '\\')"
+	if len(e.Line) == 0 {
+		return m
+	}
+	return m + ": " + string(e.Line)
+}

vendor/github.com/sourcegraph/go-diff/diff/print.go

@@ -0,0 +1,141 @@
+package diff
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"path/filepath"
+	"time"
+)
+
+// PrintMultiFileDiff prints a multi-file diff in unified diff format.
+func PrintMultiFileDiff(ds []*FileDiff) ([]byte, error) {
+	var buf bytes.Buffer
+	for _, d := range ds {
+		diff, err := PrintFileDiff(d)
+		if err != nil {
+			return nil, err
+		}
+		if _, err := buf.Write(diff); err != nil {
+			return nil, err
+		}
+	}
+	return buf.Bytes(), nil
+}
+
+// PrintFileDiff prints a FileDiff in unified diff format.
+//
+// TODO(sqs): handle escaping whitespace/etc. chars in filenames
+func PrintFileDiff(d *FileDiff) ([]byte, error) {
+	var buf bytes.Buffer
+
+	for _, xheader := range d.Extended {
+		if _, err := fmt.Fprintln(&buf, xheader); err != nil {
+			return nil, err
+		}
+	}
+
+	// FileDiff is added/deleted file
+	// No further hunks printing needed
+	if d.NewName == "" {
+		_, err := fmt.Fprintf(&buf, onlyInMessage, filepath.Dir(d.OrigName), filepath.Base(d.OrigName))
+		if err != nil {
+			return nil, err
+		}
+		return buf.Bytes(), nil
+	}
+
+	if d.Hunks == nil {
+		return buf.Bytes(), nil
+	}
+
+	if err := printFileHeader(&buf, "--- ", d.OrigName, d.OrigTime); err != nil {
+		return nil, err
+	}
+	if err := printFileHeader(&buf, "+++ ", d.NewName, d.NewTime); err != nil {
+		return nil, err
+	}
+
+	ph, err := PrintHunks(d.Hunks)
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := buf.Write(ph); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func printFileHeader(w io.Writer, prefix string, filename string, timestamp *time.Time) error {
+	if _, err := fmt.Fprint(w, prefix, filename); err != nil {
+		return err
+	}
+	if timestamp != nil {
+		if _, err := fmt.Fprint(w, "\t", timestamp.Format(diffTimeFormatLayout)); err != nil {
+			return err
+		}
+	}
+	if _, err := fmt.Fprintln(w); err != nil {
+		return err
+	}
+	return nil
+}
+
+// PrintHunks prints diff hunks in unified diff format.
+func PrintHunks(hunks []*Hunk) ([]byte, error) {
+	var buf bytes.Buffer
+	for _, hunk := range hunks {
+		_, err := fmt.Fprintf(&buf,
+			"@@ -%d,%d +%d,%d @@", hunk.OrigStartLine, hunk.OrigLines, hunk.NewStartLine, hunk.NewLines,
+		)
+		if err != nil {
+			return nil, err
+		}
+		if hunk.Section != "" {
+			_, err := fmt.Fprint(&buf, " ", hunk.Section)
+			if err != nil {
+				return nil, err
+			}
+		}
+		if _, err := fmt.Fprintln(&buf); err != nil {
+			return nil, err
+		}
+
+		if hunk.OrigNoNewlineAt == 0 {
+			if _, err := buf.Write(hunk.Body); err != nil {
+				return nil, err
+			}
+		} else {
+			if _, err := buf.Write(hunk.Body[:hunk.OrigNoNewlineAt]); err != nil {
+				return nil, err
+			}
+			if err := printNoNewlineMessage(&buf); err != nil {
+				return nil, err
+			}
+			if _, err := buf.Write(hunk.Body[hunk.OrigNoNewlineAt:]); err != nil {
+				return nil, err
+			}
+		}
+
+		if !bytes.HasSuffix(hunk.Body, []byte{'\n'}) {
+			if _, err := fmt.Fprintln(&buf); err != nil {
+				return nil, err
+			}
+			if err := printNoNewlineMessage(&buf); err != nil {
+				return nil, err
+			}
+		}
+	}
+	return buf.Bytes(), nil
+}
+
+func printNoNewlineMessage(w io.Writer) error {
+	if _, err := w.Write([]byte(noNewlineMessage)); err != nil {
+		return err
+	}
+	if _, err := fmt.Fprintln(w); err != nil {
+		return err
+	}
+	return nil
+}

vendor/github.com/sourcegraph/go-diff/diff/reader_util.go

@@ -0,0 +1,37 @@
+package diff
+
+import (
+	"bufio"
+	"io"
+)
+
+// readLine is a helper that mimics the functionality of calling bufio.Scanner.Scan() and
+// bufio.Scanner.Bytes(), but without the token size limitation. It will read and return
+// the next line in the Reader with the trailing newline stripped. It will return an
+// io.EOF error when there is nothing left to read (at the start of the function call). It
+// will return any other errors it receives from the underlying call to ReadBytes.
+func readLine(r *bufio.Reader) ([]byte, error) {
+	line_, err := r.ReadBytes('\n')
+	if err == io.EOF {
+		if len(line_) == 0 {
+			return nil, io.EOF
+		}
+
+		// ReadBytes returned io.EOF, because it didn't find another newline, but there is
+		// still the remainder of the file to return as a line.
+		line := line_
+		return line, nil
+	} else if err != nil {
+		return nil, err
+	}
+	line := line_[0 : len(line_)-1]
+	return dropCR(line), nil
+}
+
+// dropCR drops a terminal \r from the data.
+func dropCR(data []byte) []byte {
+	if len(data) > 0 && data[len(data)-1] == '\r' {
+		return data[0 : len(data)-1]
+	}
+	return data
+}