Adding upstream version 9.0.0.HEADupstream/9.0.0upstreamdebian

Signed-off-by: Daniel Baumann <daniel@debian.org>

4 files changed, 504 insertions, 0 deletions

diff --git a/modules/git/foreachref/format.go b/modules/git/foreachref/format.go
new file mode 100644
index 0000000..97e8ee4
--- /dev/null
+++ b/modules/git/foreachref/format.go
@@ -0,0 +1,83 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package foreachref
+
+import (
+	"encoding/hex"
+	"fmt"
+	"io"
+	"strings"
+)
+
+var (
+	nullChar     = []byte("\x00")
+	dualNullChar = []byte("\x00\x00")
+)
+
+// Format supports specifying and parsing an output format for 'git
+// for-each-ref'. See See git-for-each-ref(1) for available fields.
+type Format struct {
+	// fieldNames hold %(fieldname)s to be passed to the '--format' flag of
+	// for-each-ref. See git-for-each-ref(1) for available fields.
+	fieldNames []string
+
+	// fieldDelim is the character sequence that is used to separate fields
+	// for each reference. fieldDelim and refDelim should be selected to not
+	// interfere with each other and to not be present in field values.
+	fieldDelim []byte
+	// fieldDelimStr is a string representation of fieldDelim. Used to save
+	// us from repetitive reallocation whenever we need the delimiter as a
+	// string.
+	fieldDelimStr string
+	// refDelim is the character sequence used to separate reference from
+	// each other in the output. fieldDelim and refDelim should be selected
+	// to not interfere with each other and to not be present in field
+	// values.
+	refDelim []byte
+}
+
+// NewFormat creates a forEachRefFormat using the specified fieldNames. See
+// git-for-each-ref(1) for available fields.
+func NewFormat(fieldNames ...string) Format {
+	return Format{
+		fieldNames:    fieldNames,
+		fieldDelim:    nullChar,
+		fieldDelimStr: string(nullChar),
+		refDelim:      dualNullChar,
+	}
+}
+
+// Flag returns a for-each-ref --format flag value that captures the fieldNames.
+func (f Format) Flag() string {
+	var formatFlag strings.Builder
+	for i, field := range f.fieldNames {
+		// field key and field value
+		formatFlag.WriteString(fmt.Sprintf("%s %%(%s)", field, field))
+
+		if i < len(f.fieldNames)-1 {
+			// note: escape delimiters to allow control characters as
+			// delimiters. For example, '%00' for null character or '%0a'
+			// for newline.
+			formatFlag.WriteString(f.hexEscaped(f.fieldDelim))
+		}
+	}
+	formatFlag.WriteString(f.hexEscaped(f.refDelim))
+	return formatFlag.String()
+}
+
+// Parser returns a Parser capable of parsing 'git for-each-ref' output produced
+// with this Format.
+func (f Format) Parser(r io.Reader) *Parser {
+	return NewParser(r, f)
+}
+
+// hexEscaped produces hex-escpaed characters from a string. For example, "\n\0"
+// would turn into "%0a%00".
+func (f Format) hexEscaped(delim []byte) string {
+	escaped := ""
+	for i := 0; i < len(delim); i++ {
+		escaped += "%" + hex.EncodeToString([]byte{delim[i]})
+	}
+	return escaped
+}
diff --git a/modules/git/foreachref/format_test.go b/modules/git/foreachref/format_test.go
new file mode 100644
index 0000000..8ff2393
--- /dev/null
+++ b/modules/git/foreachref/format_test.go
@@ -0,0 +1,66 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package foreachref_test
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/modules/git/foreachref"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFormat_Flag(t *testing.T) {
+	tests := []struct {
+		name string
+
+		givenFormat foreachref.Format
+
+		wantFlag string
+	}{
+		{
+			name: "references are delimited by dual null chars",
+
+			// no reference fields requested
+			givenFormat: foreachref.NewFormat(),
+
+			// only a reference delimiter field in --format
+			wantFlag: "%00%00",
+		},
+
+		{
+			name: "a field is a space-separated key-value pair",
+
+			givenFormat: foreachref.NewFormat("refname:short"),
+
+			// only a reference delimiter field
+			wantFlag: "refname:short %(refname:short)%00%00",
+		},
+
+		{
+			name: "fields are separated by a null char field-delimiter",
+
+			givenFormat: foreachref.NewFormat("refname:short", "author"),
+
+			wantFlag: "refname:short %(refname:short)%00author %(author)%00%00",
+		},
+
+		{
+			name: "multiple fields",
+
+			givenFormat: foreachref.NewFormat("refname:lstrip=2", "objecttype", "objectname"),
+
+			wantFlag: "refname:lstrip=2 %(refname:lstrip=2)%00objecttype %(objecttype)%00objectname %(objectname)%00%00",
+		},
+	}
+
+	for _, test := range tests {
+		tc := test // don't close over loop variable
+		t.Run(tc.name, func(t *testing.T) {
+			gotFlag := tc.givenFormat.Flag()
+
+			require.Equal(t, tc.wantFlag, gotFlag, "unexpected for-each-ref --format string. wanted: '%s', got: '%s'", tc.wantFlag, gotFlag)
+		})
+	}
+}
diff --git a/modules/git/foreachref/parser.go b/modules/git/foreachref/parser.go
new file mode 100644
index 0000000..de69eaa
--- /dev/null
+++ b/modules/git/foreachref/parser.go
@@ -0,0 +1,128 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package foreachref
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// Parser parses 'git for-each-ref' output according to a given output Format.
+type Parser struct {
+	//  tokenizes 'git for-each-ref' output into "reference paragraphs".
+	scanner *bufio.Scanner
+
+	// format represents the '--format' string that describes the expected
+	// 'git for-each-ref' output structure.
+	format Format
+
+	// err holds the last encountered error during parsing.
+	err error
+}
+
+// NewParser creates a 'git for-each-ref' output parser that will parse all
+// references in the provided Reader. The references in the output are assumed
+// to follow the specified Format.
+func NewParser(r io.Reader, format Format) *Parser {
+	scanner := bufio.NewScanner(r)
+
+	// in addition to the reference delimiter we specified in the --format,
+	// `git for-each-ref` will always add a newline after every reference.
+	refDelim := make([]byte, 0, len(format.refDelim)+1)
+	refDelim = append(refDelim, format.refDelim...)
+	refDelim = append(refDelim, '\n')
+
+	// Split input into delimiter-separated "reference blocks".
+	scanner.Split(
+		func(data []byte, atEOF bool) (advance int, token []byte, err error) {
+			// Scan until delimiter, marking end of reference.
+			delimIdx := bytes.Index(data, refDelim)
+			if delimIdx >= 0 {
+				token := data[:delimIdx]
+				advance := delimIdx + len(refDelim)
+				return advance, token, nil
+			}
+			// If we're at EOF, we have a final, non-terminated reference. Return it.
+			if atEOF {
+				return len(data), data, nil
+			}
+			// Not yet a full field. Request more data.
+			return 0, nil, nil
+		})
+
+	return &Parser{
+		scanner: scanner,
+		format:  format,
+		err:     nil,
+	}
+}
+
+// Next returns the next reference as a collection of key-value pairs. nil
+// denotes EOF but is also returned on errors. The Err method should always be
+// consulted after Next returning nil.
+//
+// It could, for example return something like:
+//
+//	{ "objecttype": "tag", "refname:short": "v1.16.4", "object": "f460b7543ed500e49c133c2cd85c8c55ee9dbe27" }
+func (p *Parser) Next() map[string]string {
+	if !p.scanner.Scan() {
+		return nil
+	}
+	fields, err := p.parseRef(p.scanner.Text())
+	if err != nil {
+		p.err = err
+		return nil
+	}
+	return fields
+}
+
+// Err returns the latest encountered parsing error.
+func (p *Parser) Err() error {
+	return p.err
+}
+
+// parseRef parses out all key-value pairs from a single reference block, such as
+//
+//	"objecttype tag\0refname:short v1.16.4\0object f460b7543ed500e49c133c2cd85c8c55ee9dbe27"
+func (p *Parser) parseRef(refBlock string) (map[string]string, error) {
+	if refBlock == "" {
+		// must be at EOF
+		return nil, nil
+	}
+
+	fieldValues := make(map[string]string)
+
+	fields := strings.Split(refBlock, p.format.fieldDelimStr)
+	if len(fields) != len(p.format.fieldNames) {
+		return nil, fmt.Errorf("unexpected number of reference fields: wanted %d, was %d",
+			len(fields), len(p.format.fieldNames))
+	}
+	for i, field := range fields {
+		field = strings.TrimSpace(field)
+
+		var fieldKey string
+		var fieldVal string
+		firstSpace := strings.Index(field, " ")
+		if firstSpace > 0 {
+			fieldKey = field[:firstSpace]
+			fieldVal = field[firstSpace+1:]
+		} else {
+			// could be the case if the requested field had no value
+			fieldKey = field
+		}
+
+		// enforce the format order of fields
+		if p.format.fieldNames[i] != fieldKey {
+			return nil, fmt.Errorf("unexpected field name at position %d: wanted: '%s', was: '%s'",
+				i, p.format.fieldNames[i], fieldKey)
+		}
+
+		fieldValues[fieldKey] = fieldVal
+	}
+
+	return fieldValues, nil
+}
diff --git a/modules/git/foreachref/parser_test.go b/modules/git/foreachref/parser_test.go
new file mode 100644
index 0000000..7a37ced
--- /dev/null
+++ b/modules/git/foreachref/parser_test.go
@@ -0,0 +1,227 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package foreachref_test
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/modules/git/foreachref"
+	"code.gitea.io/gitea/modules/json"
+
+	"github.com/stretchr/testify/require"
+)
+
+type refSlice = []map[string]string
+
+func TestParser(t *testing.T) {
+	tests := []struct {
+		name string
+
+		givenFormat foreachref.Format
+		givenInput  io.Reader
+
+		wantRefs    refSlice
+		wantErr     bool
+		expectedErr error
+	}{
+		// this would, for example, be the result when running `git
+		// for-each-ref refs/tags` on a repo without tags.
+		{
+			name: "no references on empty input",
+
+			givenFormat: foreachref.NewFormat("refname:short"),
+			givenInput:  strings.NewReader(``),
+
+			wantRefs: []map[string]string{},
+		},
+
+		// note: `git for-each-ref` will add a newline between every
+		// reference (in addition to the ref-delimiter we've chosen)
+		{
+			name: "single field requested, single reference in output",
+
+			givenFormat: foreachref.NewFormat("refname:short"),
+			givenInput:  strings.NewReader("refname:short v0.0.1\x00\x00" + "\n"),
+
+			wantRefs: []map[string]string{
+				{"refname:short": "v0.0.1"},
+			},
+		},
+		{
+			name: "single field requested, multiple references in output",
+
+			givenFormat: foreachref.NewFormat("refname:short"),
+			givenInput: strings.NewReader(
+				"refname:short v0.0.1\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00\x00" + "\n"),
+
+			wantRefs: []map[string]string{
+				{"refname:short": "v0.0.1"},
+				{"refname:short": "v0.0.2"},
+				{"refname:short": "v0.0.3"},
+			},
+		},
+
+		{
+			name: "multiple fields requested for each reference",
+
+			givenFormat: foreachref.NewFormat("refname:short", "objecttype", "objectname"),
+			givenInput: strings.NewReader(
+
+				"refname:short v0.0.1\x00objecttype commit\x00objectname 7b2c5ac9fc04fc5efafb60700713d4fa609b777b\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00objecttype commit\x00objectname a1f051bc3eba734da4772d60e2d677f47cf93ef4\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00objecttype commit\x00objectname ef82de70bb3f60c65fb8eebacbb2d122ef517385\x00\x00" + "\n",
+			),
+
+			wantRefs: []map[string]string{
+				{
+					"refname:short": "v0.0.1",
+					"objecttype":    "commit",
+					"objectname":    "7b2c5ac9fc04fc5efafb60700713d4fa609b777b",
+				},
+				{
+					"refname:short": "v0.0.2",
+					"objecttype":    "commit",
+					"objectname":    "a1f051bc3eba734da4772d60e2d677f47cf93ef4",
+				},
+				{
+					"refname:short": "v0.0.3",
+					"objecttype":    "commit",
+					"objectname":    "ef82de70bb3f60c65fb8eebacbb2d122ef517385",
+				},
+			},
+		},
+
+		{
+			name: "must handle multi-line fields such as 'content'",
+
+			givenFormat: foreachref.NewFormat("refname:short", "contents", "author"),
+			givenInput: strings.NewReader(
+				"refname:short v0.0.1\x00contents Create new buffer if not present yet (#549)\n\nFixes a nil dereference when ProcessFoo is used\nwith multiple commands.\x00author Foo Bar <foo@bar.com> 1507832733 +0200\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00contents Update CI config (#651)\n\n\x00author John Doe <john.doe@foo.com> 1521643174 +0000\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00contents Fixed code sample for bash completion (#687)\n\n\x00author Foo Baz <foo@baz.com> 1524836750 +0200\x00\x00" + "\n",
+			),
+
+			wantRefs: []map[string]string{
+				{
+					"refname:short": "v0.0.1",
+					"contents":      "Create new buffer if not present yet (#549)\n\nFixes a nil dereference when ProcessFoo is used\nwith multiple commands.",
+					"author":        "Foo Bar <foo@bar.com> 1507832733 +0200",
+				},
+				{
+					"refname:short": "v0.0.2",
+					"contents":      "Update CI config (#651)",
+					"author":        "John Doe <john.doe@foo.com> 1521643174 +0000",
+				},
+				{
+					"refname:short": "v0.0.3",
+					"contents":      "Fixed code sample for bash completion (#687)",
+					"author":        "Foo Baz <foo@baz.com> 1524836750 +0200",
+				},
+			},
+		},
+
+		{
+			name: "must handle fields without values",
+
+			givenFormat: foreachref.NewFormat("refname:short", "object", "objecttype"),
+			givenInput: strings.NewReader(
+				"refname:short v0.0.1\x00object \x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00object \x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00object \x00objecttype commit\x00\x00" + "\n",
+			),
+
+			wantRefs: []map[string]string{
+				{
+					"refname:short": "v0.0.1",
+					"object":        "",
+					"objecttype":    "commit",
+				},
+				{
+					"refname:short": "v0.0.2",
+					"object":        "",
+					"objecttype":    "commit",
+				},
+				{
+					"refname:short": "v0.0.3",
+					"object":        "",
+					"objecttype":    "commit",
+				},
+			},
+		},
+
+		{
+			name: "must fail when the number of fields in the input doesn't match expected format",
+
+			givenFormat: foreachref.NewFormat("refname:short", "objecttype", "objectname"),
+			givenInput: strings.NewReader(
+				"refname:short v0.0.1\x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00objecttype commit\x00\x00" + "\n",
+			),
+
+			wantErr:     true,
+			expectedErr: errors.New("unexpected number of reference fields: wanted 2, was 3"),
+		},
+
+		{
+			name: "must fail input fields don't match expected format",
+
+			givenFormat: foreachref.NewFormat("refname:short", "objectname"),
+			givenInput: strings.NewReader(
+				"refname:short v0.0.1\x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.2\x00objecttype commit\x00\x00" + "\n" +
+					"refname:short v0.0.3\x00objecttype commit\x00\x00" + "\n",
+			),
+
+			wantErr:     true,
+			expectedErr: errors.New("unexpected field name at position 1: wanted: 'objectname', was: 'objecttype'"),
+		},
+	}
+
+	for _, test := range tests {
+		tc := test // don't close over loop variable
+		t.Run(tc.name, func(t *testing.T) {
+			parser := tc.givenFormat.Parser(tc.givenInput)
+
+			//
+			// parse references from input
+			//
+			gotRefs := make([]map[string]string, 0)
+			for {
+				ref := parser.Next()
+				if ref == nil {
+					break
+				}
+				gotRefs = append(gotRefs, ref)
+			}
+			err := parser.Err()
+
+			//
+			// verify expectations
+			//
+			if tc.wantErr {
+				require.Error(t, err)
+				require.EqualError(t, err, tc.expectedErr.Error())
+			} else {
+				require.NoError(t, err, "for-each-ref parser unexpectedly failed with: %v", err)
+				require.Equal(t, tc.wantRefs, gotRefs, "for-each-ref parser produced unexpected reference set. wanted: %v, got: %v", pretty(tc.wantRefs), pretty(gotRefs))
+			}
+		})
+	}
+}
+
+func pretty(v any) string {
+	data, err := json.MarshalIndent(v, "", "  ")
+	if err != nil {
+		// shouldn't happen
+		panic(fmt.Sprintf("json-marshalling failed: %v", err))
+	}
+	return string(data)
+}