Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

1 files changed, 1033 insertions, 0 deletions

diff --git a/vendor/github.com/peterh/liner/line.go b/vendor/github.com/peterh/liner/line.go
new file mode 100644
index 000000000..903dd240d
--- /dev/null
+++ b/vendor/github.com/peterh/liner/line.go
@@ -0,0 +1,1033 @@
+// +build windows linux darwin openbsd freebsd netbsd
+
+package liner
+
+import (
+	"container/ring"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+type action int
+
+const (
+	left action = iota
+	right
+	up
+	down
+	home
+	end
+	insert
+	del
+	pageUp
+	pageDown
+	f1
+	f2
+	f3
+	f4
+	f5
+	f6
+	f7
+	f8
+	f9
+	f10
+	f11
+	f12
+	altB
+	altF
+	altY
+	shiftTab
+	wordLeft
+	wordRight
+	winch
+	unknown
+)
+
+const (
+	ctrlA = 1
+	ctrlB = 2
+	ctrlC = 3
+	ctrlD = 4
+	ctrlE = 5
+	ctrlF = 6
+	ctrlG = 7
+	ctrlH = 8
+	tab   = 9
+	lf    = 10
+	ctrlK = 11
+	ctrlL = 12
+	cr    = 13
+	ctrlN = 14
+	ctrlO = 15
+	ctrlP = 16
+	ctrlQ = 17
+	ctrlR = 18
+	ctrlS = 19
+	ctrlT = 20
+	ctrlU = 21
+	ctrlV = 22
+	ctrlW = 23
+	ctrlX = 24
+	ctrlY = 25
+	ctrlZ = 26
+	esc   = 27
+	bs    = 127
+)
+
+const (
+	beep = "\a"
+)
+
+type tabDirection int
+
+const (
+	tabForward tabDirection = iota
+	tabReverse
+)
+
+func (s *State) refresh(prompt []rune, buf []rune, pos int) error {
+	if s.multiLineMode {
+		return s.refreshMultiLine(prompt, buf, pos)
+	} else {
+		return s.refreshSingleLine(prompt, buf, pos)
+	}
+}
+
+func (s *State) refreshSingleLine(prompt []rune, buf []rune, pos int) error {
+	s.cursorPos(0)
+	_, err := fmt.Print(string(prompt))
+	if err != nil {
+		return err
+	}
+
+	pLen := countGlyphs(prompt)
+	bLen := countGlyphs(buf)
+	pos = countGlyphs(buf[:pos])
+	if pLen+bLen < s.columns {
+		_, err = fmt.Print(string(buf))
+		s.eraseLine()
+		s.cursorPos(pLen + pos)
+	} else {
+		// Find space available
+		space := s.columns - pLen
+		space-- // space for cursor
+		start := pos - space/2
+		end := start + space
+		if end > bLen {
+			end = bLen
+			start = end - space
+		}
+		if start < 0 {
+			start = 0
+			end = space
+		}
+		pos -= start
+
+		// Leave space for markers
+		if start > 0 {
+			start++
+		}
+		if end < bLen {
+			end--
+		}
+		startRune := len(getPrefixGlyphs(buf, start))
+		line := getPrefixGlyphs(buf[startRune:], end-start)
+
+		// Output
+		if start > 0 {
+			fmt.Print("{")
+		}
+		fmt.Print(string(line))
+		if end < bLen {
+			fmt.Print("}")
+		}
+
+		// Set cursor position
+		s.eraseLine()
+		s.cursorPos(pLen + pos)
+	}
+	return err
+}
+
+func (s *State) refreshMultiLine(prompt []rune, buf []rune, pos int) error {
+	promptColumns := countMultiLineGlyphs(prompt, s.columns, 0)
+	totalColumns := countMultiLineGlyphs(buf, s.columns, promptColumns)
+	totalRows := (totalColumns + s.columns - 1) / s.columns
+	maxRows := s.maxRows
+	if totalRows > s.maxRows {
+		s.maxRows = totalRows
+	}
+	cursorRows := s.cursorRows
+	if cursorRows == 0 {
+		cursorRows = 1
+	}
+
+	/* First step: clear all the lines used before. To do so start by
+	* going to the last row. */
+	if maxRows-cursorRows > 0 {
+		s.moveDown(maxRows - cursorRows)
+	}
+
+	/* Now for every row clear it, go up. */
+	for i := 0; i < maxRows-1; i++ {
+		s.cursorPos(0)
+		s.eraseLine()
+		s.moveUp(1)
+	}
+
+	/* Clean the top line. */
+	s.cursorPos(0)
+	s.eraseLine()
+
+	/* Write the prompt and the current buffer content */
+	if _, err := fmt.Print(string(prompt)); err != nil {
+		return err
+	}
+	if _, err := fmt.Print(string(buf)); err != nil {
+		return err
+	}
+
+	/* If we are at the very end of the screen with our prompt, we need to
+	 * emit a newline and move the prompt to the first column. */
+	cursorColumns := countMultiLineGlyphs(buf[:pos], s.columns, promptColumns)
+	if cursorColumns == totalColumns && totalColumns%s.columns == 0 {
+		s.emitNewLine()
+		s.cursorPos(0)
+		totalRows++
+		if totalRows > s.maxRows {
+			s.maxRows = totalRows
+		}
+	}
+
+	/* Move cursor to right position. */
+	cursorRows = (cursorColumns + s.columns) / s.columns
+	if s.cursorRows > 0 && totalRows-cursorRows > 0 {
+		s.moveUp(totalRows - cursorRows)
+	}
+	/* Set column. */
+	s.cursorPos(cursorColumns % s.columns)
+
+	s.cursorRows = cursorRows
+	return nil
+}
+
+func (s *State) resetMultiLine(prompt []rune, buf []rune, pos int) {
+	columns := countMultiLineGlyphs(prompt, s.columns, 0)
+	columns = countMultiLineGlyphs(buf[:pos], s.columns, columns)
+	columns += 2 // ^C
+	cursorRows := (columns + s.columns) / s.columns
+	if s.maxRows-cursorRows > 0 {
+		for i := 0; i < s.maxRows-cursorRows; i++ {
+			fmt.Println() // always moves the cursor down or scrolls the window up as needed
+		}
+	}
+	s.maxRows = 1
+	s.cursorRows = 0
+}
+
+func longestCommonPrefix(strs []string) string {
+	if len(strs) == 0 {
+		return ""
+	}
+	longest := strs[0]
+
+	for _, str := range strs[1:] {
+		for !strings.HasPrefix(str, longest) {
+			longest = longest[:len(longest)-1]
+		}
+	}
+	// Remove trailing partial runes
+	longest = strings.TrimRight(longest, "\uFFFD")
+	return longest
+}
+
+func (s *State) circularTabs(items []string) func(tabDirection) (string, error) {
+	item := -1
+	return func(direction tabDirection) (string, error) {
+		if direction == tabForward {
+			if item < len(items)-1 {
+				item++
+			} else {
+				item = 0
+			}
+		} else if direction == tabReverse {
+			if item > 0 {
+				item--
+			} else {
+				item = len(items) - 1
+			}
+		}
+		return items[item], nil
+	}
+}
+
+func calculateColumns(screenWidth int, items []string) (numColumns, numRows, maxWidth int) {
+	for _, item := range items {
+		if len(item) >= screenWidth {
+			return 1, len(items), screenWidth - 1
+		}
+		if len(item) >= maxWidth {
+			maxWidth = len(item) + 1
+		}
+	}
+
+	numColumns = screenWidth / maxWidth
+	numRows = len(items) / numColumns
+	if len(items)%numColumns > 0 {
+		numRows++
+	}
+
+	if len(items) <= numColumns {
+		maxWidth = 0
+	}
+
+	return
+}
+
+func (s *State) printedTabs(items []string) func(tabDirection) (string, error) {
+	numTabs := 1
+	prefix := longestCommonPrefix(items)
+	return func(direction tabDirection) (string, error) {
+		if len(items) == 1 {
+			return items[0], nil
+		}
+
+		if numTabs == 2 {
+			if len(items) > 100 {
+				fmt.Printf("\nDisplay all %d possibilities? (y or n) ", len(items))
+			prompt:
+				for {
+					next, err := s.readNext()
+					if err != nil {
+						return prefix, err
+					}
+
+					if key, ok := next.(rune); ok {
+						switch key {
+						case 'n', 'N':
+							return prefix, nil
+						case 'y', 'Y':
+							break prompt
+						case ctrlC, ctrlD, cr, lf:
+							s.restartPrompt()
+						}
+					}
+				}
+			}
+			fmt.Println("")
+
+			numColumns, numRows, maxWidth := calculateColumns(s.columns, items)
+
+			for i := 0; i < numRows; i++ {
+				for j := 0; j < numColumns*numRows; j += numRows {
+					if i+j < len(items) {
+						if maxWidth > 0 {
+							fmt.Printf("%-*.[1]*s", maxWidth, items[i+j])
+						} else {
+							fmt.Printf("%v ", items[i+j])
+						}
+					}
+				}
+				fmt.Println("")
+			}
+		} else {
+			numTabs++
+		}
+		return prefix, nil
+	}
+}
+
+func (s *State) tabComplete(p []rune, line []rune, pos int) ([]rune, int, interface{}, error) {
+	if s.completer == nil {
+		return line, pos, rune(esc), nil
+	}
+	head, list, tail := s.completer(string(line), pos)
+	if len(list) <= 0 {
+		return line, pos, rune(esc), nil
+	}
+	hl := utf8.RuneCountInString(head)
+	if len(list) == 1 {
+		s.refresh(p, []rune(head+list[0]+tail), hl+utf8.RuneCountInString(list[0]))
+		return []rune(head + list[0] + tail), hl + utf8.RuneCountInString(list[0]), rune(esc), nil
+	}
+
+	direction := tabForward
+	tabPrinter := s.circularTabs(list)
+	if s.tabStyle == TabPrints {
+		tabPrinter = s.printedTabs(list)
+	}
+
+	for {
+		pick, err := tabPrinter(direction)
+		if err != nil {
+			return line, pos, rune(esc), err
+		}
+		s.refresh(p, []rune(head+pick+tail), hl+utf8.RuneCountInString(pick))
+
+		next, err := s.readNext()
+		if err != nil {
+			return line, pos, rune(esc), err
+		}
+		if key, ok := next.(rune); ok {
+			if key == tab {
+				direction = tabForward
+				continue
+			}
+			if key == esc {
+				return line, pos, rune(esc), nil
+			}
+		}
+		if a, ok := next.(action); ok && a == shiftTab {
+			direction = tabReverse
+			continue
+		}
+		return []rune(head + pick + tail), hl + utf8.RuneCountInString(pick), next, nil
+	}
+	// Not reached
+	return line, pos, rune(esc), nil
+}
+
+// reverse intelligent search, implements a bash-like history search.
+func (s *State) reverseISearch(origLine []rune, origPos int) ([]rune, int, interface{}, error) {
+	p := "(reverse-i-search)`': "
+	s.refresh([]rune(p), origLine, origPos)
+
+	line := []rune{}
+	pos := 0
+	foundLine := string(origLine)
+	foundPos := origPos
+
+	getLine := func() ([]rune, []rune, int) {
+		search := string(line)
+		prompt := "(reverse-i-search)`%s': "
+		return []rune(fmt.Sprintf(prompt, search)), []rune(foundLine), foundPos
+	}
+
+	history, positions := s.getHistoryByPattern(string(line))
+	historyPos := len(history) - 1
+
+	for {
+		next, err := s.readNext()
+		if err != nil {
+			return []rune(foundLine), foundPos, rune(esc), err
+		}
+
+		switch v := next.(type) {
+		case rune:
+			switch v {
+			case ctrlR: // Search backwards
+				if historyPos > 0 && historyPos < len(history) {
+					historyPos--
+					foundLine = history[historyPos]
+					foundPos = positions[historyPos]
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlS: // Search forward
+				if historyPos < len(history)-1 && historyPos >= 0 {
+					historyPos++
+					foundLine = history[historyPos]
+					foundPos = positions[historyPos]
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlH, bs: // Backspace
+				if pos <= 0 {
+					fmt.Print(beep)
+				} else {
+					n := len(getSuffixGlyphs(line[:pos], 1))
+					line = append(line[:pos-n], line[pos:]...)
+					pos -= n
+
+					// For each char deleted, display the last matching line of history
+					history, positions := s.getHistoryByPattern(string(line))
+					historyPos = len(history) - 1
+					if len(history) > 0 {
+						foundLine = history[historyPos]
+						foundPos = positions[historyPos]
+					} else {
+						foundLine = ""
+						foundPos = 0
+					}
+				}
+			case ctrlG: // Cancel
+				return origLine, origPos, rune(esc), err
+
+			case tab, cr, lf, ctrlA, ctrlB, ctrlD, ctrlE, ctrlF, ctrlK,
+				ctrlL, ctrlN, ctrlO, ctrlP, ctrlQ, ctrlT, ctrlU, ctrlV, ctrlW, ctrlX, ctrlY, ctrlZ:
+				fallthrough
+			case 0, ctrlC, esc, 28, 29, 30, 31:
+				return []rune(foundLine), foundPos, next, err
+			default:
+				line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
+				pos++
+
+				// For each keystroke typed, display the last matching line of history
+				history, positions = s.getHistoryByPattern(string(line))
+				historyPos = len(history) - 1
+				if len(history) > 0 {
+					foundLine = history[historyPos]
+					foundPos = positions[historyPos]
+				} else {
+					foundLine = ""
+					foundPos = 0
+				}
+			}
+		case action:
+			return []rune(foundLine), foundPos, next, err
+		}
+		s.refresh(getLine())
+	}
+}
+
+// addToKillRing adds some text to the kill ring. If mode is 0 it adds it to a
+// new node in the end of the kill ring, and move the current pointer to the new
+// node. If mode is 1 or 2 it appends or prepends the text to the current entry
+// of the killRing.
+func (s *State) addToKillRing(text []rune, mode int) {
+	// Don't use the same underlying array as text
+	killLine := make([]rune, len(text))
+	copy(killLine, text)
+
+	// Point killRing to a newNode, procedure depends on the killring state and
+	// append mode.
+	if mode == 0 { // Add new node to killRing
+		if s.killRing == nil { // if killring is empty, create a new one
+			s.killRing = ring.New(1)
+		} else if s.killRing.Len() >= KillRingMax { // if killring is "full"
+			s.killRing = s.killRing.Next()
+		} else { // Normal case
+			s.killRing.Link(ring.New(1))
+			s.killRing = s.killRing.Next()
+		}
+	} else {
+		if s.killRing == nil { // if killring is empty, create a new one
+			s.killRing = ring.New(1)
+			s.killRing.Value = []rune{}
+		}
+		if mode == 1 { // Append to last entry
+			killLine = append(s.killRing.Value.([]rune), killLine...)
+		} else if mode == 2 { // Prepend to last entry
+			killLine = append(killLine, s.killRing.Value.([]rune)...)
+		}
+	}
+
+	// Save text in the current killring node
+	s.killRing.Value = killLine
+}
+
+func (s *State) yank(p []rune, text []rune, pos int) ([]rune, int, interface{}, error) {
+	if s.killRing == nil {
+		return text, pos, rune(esc), nil
+	}
+
+	lineStart := text[:pos]
+	lineEnd := text[pos:]
+	var line []rune
+
+	for {
+		value := s.killRing.Value.([]rune)
+		line = make([]rune, 0)
+		line = append(line, lineStart...)
+		line = append(line, value...)
+		line = append(line, lineEnd...)
+
+		pos = len(lineStart) + len(value)
+		s.refresh(p, line, pos)
+
+		next, err := s.readNext()
+		if err != nil {
+			return line, pos, next, err
+		}
+
+		switch v := next.(type) {
+		case rune:
+			return line, pos, next, nil
+		case action:
+			switch v {
+			case altY:
+				s.killRing = s.killRing.Prev()
+			default:
+				return line, pos, next, nil
+			}
+		}
+	}
+
+	return line, pos, esc, nil
+}
+
+// Prompt displays p and returns a line of user input, not including a trailing
+// newline character. An io.EOF error is returned if the user signals end-of-file
+// by pressing Ctrl-D. Prompt allows line editing if the terminal supports it.
+func (s *State) Prompt(prompt string) (string, error) {
+	return s.PromptWithSuggestion(prompt, "", 0)
+}
+
+// PromptWithSuggestion displays prompt and an editable text with cursor at
+// given position. The cursor will be set to the end of the line if given position
+// is negative or greater than length of text. Returns a line of user input, not
+// including a trailing newline character. An io.EOF error is returned if the user
+// signals end-of-file by pressing Ctrl-D.
+func (s *State) PromptWithSuggestion(prompt string, text string, pos int) (string, error) {
+	if s.inputRedirected || !s.terminalSupported {
+		return s.promptUnsupported(prompt)
+	}
+	if s.outputRedirected {
+		return "", ErrNotTerminalOutput
+	}
+
+	s.historyMutex.RLock()
+	defer s.historyMutex.RUnlock()
+
+	fmt.Print(prompt)
+	p := []rune(prompt)
+	var line = []rune(text)
+	historyEnd := ""
+	prefixHistory := s.getHistoryByPrefix(string(line))
+	historyPos := len(prefixHistory)
+	historyAction := false // used to mark history related actions
+	killAction := 0        // used to mark kill related actions
+
+	defer s.stopPrompt()
+
+	if pos < 0 || len(text) < pos {
+		pos = len(text)
+	}
+	if len(line) > 0 {
+		s.refresh(p, line, pos)
+	}
+
+restart:
+	s.startPrompt()
+	s.getColumns()
+
+mainLoop:
+	for {
+		next, err := s.readNext()
+	haveNext:
+		if err != nil {
+			if s.shouldRestart != nil && s.shouldRestart(err) {
+				goto restart
+			}
+			return "", err
+		}
+
+		historyAction = false
+		switch v := next.(type) {
+		case rune:
+			switch v {
+			case cr, lf:
+				if s.multiLineMode {
+					s.resetMultiLine(p, line, pos)
+				}
+				fmt.Println()
+				break mainLoop
+			case ctrlA: // Start of line
+				pos = 0
+				s.refresh(p, line, pos)
+			case ctrlE: // End of line
+				pos = len(line)
+				s.refresh(p, line, pos)
+			case ctrlB: // left
+				if pos > 0 {
+					pos -= len(getSuffixGlyphs(line[:pos], 1))
+					s.refresh(p, line, pos)
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlF: // right
+				if pos < len(line) {
+					pos += len(getPrefixGlyphs(line[pos:], 1))
+					s.refresh(p, line, pos)
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlD: // del
+				if pos == 0 && len(line) == 0 {
+					// exit
+					return "", io.EOF
+				}
+
+				// ctrlD is a potential EOF, so the rune reader shuts down.
+				// Therefore, if it isn't actually an EOF, we must re-startPrompt.
+				s.restartPrompt()
+
+				if pos >= len(line) {
+					fmt.Print(beep)
+				} else {
+					n := len(getPrefixGlyphs(line[pos:], 1))
+					line = append(line[:pos], line[pos+n:]...)
+					s.refresh(p, line, pos)
+				}
+			case ctrlK: // delete remainder of line
+				if pos >= len(line) {
+					fmt.Print(beep)
+				} else {
+					if killAction > 0 {
+						s.addToKillRing(line[pos:], 1) // Add in apend mode
+					} else {
+						s.addToKillRing(line[pos:], 0) // Add in normal mode
+					}
+
+					killAction = 2 // Mark that there was a kill action
+					line = line[:pos]
+					s.refresh(p, line, pos)
+				}
+			case ctrlP: // up
+				historyAction = true
+				if historyPos > 0 {
+					if historyPos == len(prefixHistory) {
+						historyEnd = string(line)
+					}
+					historyPos--
+					line = []rune(prefixHistory[historyPos])
+					pos = len(line)
+					s.refresh(p, line, pos)
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlN: // down
+				historyAction = true
+				if historyPos < len(prefixHistory) {
+					historyPos++
+					if historyPos == len(prefixHistory) {
+						line = []rune(historyEnd)
+					} else {
+						line = []rune(prefixHistory[historyPos])
+					}
+					pos = len(line)
+					s.refresh(p, line, pos)
+				} else {
+					fmt.Print(beep)
+				}
+			case ctrlT: // transpose prev glyph with glyph under cursor
+				if len(line) < 2 || pos < 1 {
+					fmt.Print(beep)
+				} else {
+					if pos == len(line) {
+						pos -= len(getSuffixGlyphs(line, 1))
+					}
+					prev := getSuffixGlyphs(line[:pos], 1)
+					next := getPrefixGlyphs(line[pos:], 1)
+					scratch := make([]rune, len(prev))
+					copy(scratch, prev)
+					copy(line[pos-len(prev):], next)
+					copy(line[pos-len(prev)+len(next):], scratch)
+					pos += len(next)
+					s.refresh(p, line, pos)
+				}
+			case ctrlL: // clear screen
+				s.eraseScreen()
+				s.refresh(p, line, pos)
+			case ctrlC: // reset
+				fmt.Println("^C")
+				if s.multiLineMode {
+					s.resetMultiLine(p, line, pos)
+				}
+				if s.ctrlCAborts {
+					return "", ErrPromptAborted
+				}
+				line = line[:0]
+				pos = 0
+				fmt.Print(prompt)
+				s.restartPrompt()
+			case ctrlH, bs: // Backspace
+				if pos <= 0 {
+					fmt.Print(beep)
+				} else {
+					n := len(getSuffixGlyphs(line[:pos], 1))
+					line = append(line[:pos-n], line[pos:]...)
+					pos -= n
+					s.refresh(p, line, pos)
+				}
+			case ctrlU: // Erase line before cursor
+				if killAction > 0 {
+					s.addToKillRing(line[:pos], 2) // Add in prepend mode
+				} else {
+					s.addToKillRing(line[:pos], 0) // Add in normal mode
+				}
+
+				killAction = 2 // Mark that there was some killing
+				line = line[pos:]
+				pos = 0
+				s.refresh(p, line, pos)
+			case ctrlW: // Erase word
+				if pos == 0 {
+					fmt.Print(beep)
+					break
+				}
+				// Remove whitespace to the left
+				var buf []rune // Store the deleted chars in a buffer
+				for {
+					if pos == 0 || !unicode.IsSpace(line[pos-1]) {
+						break
+					}
+					buf = append(buf, line[pos-1])
+					line = append(line[:pos-1], line[pos:]...)
+					pos--
+				}
+				// Remove non-whitespace to the left
+				for {
+					if pos == 0 || unicode.IsSpace(line[pos-1]) {
+						break
+					}
+					buf = append(buf, line[pos-1])
+					line = append(line[:pos-1], line[pos:]...)
+					pos--
+				}
+				// Invert the buffer and save the result on the killRing
+				var newBuf []rune
+				for i := len(buf) - 1; i >= 0; i-- {
+					newBuf = append(newBuf, buf[i])
+				}
+				if killAction > 0 {
+					s.addToKillRing(newBuf, 2) // Add in prepend mode
+				} else {
+					s.addToKillRing(newBuf, 0) // Add in normal mode
+				}
+				killAction = 2 // Mark that there was some killing
+
+				s.refresh(p, line, pos)
+			case ctrlY: // Paste from Yank buffer
+				line, pos, next, err = s.yank(p, line, pos)
+				goto haveNext
+			case ctrlR: // Reverse Search
+				line, pos, next, err = s.reverseISearch(line, pos)
+				s.refresh(p, line, pos)
+				goto haveNext
+			case tab: // Tab completion
+				line, pos, next, err = s.tabComplete(p, line, pos)
+				goto haveNext
+			// Catch keys that do nothing, but you don't want them to beep
+			case esc:
+				// DO NOTHING
+			// Unused keys
+			case ctrlG, ctrlO, ctrlQ, ctrlS, ctrlV, ctrlX, ctrlZ:
+				fallthrough
+			// Catch unhandled control codes (anything <= 31)
+			case 0, 28, 29, 30, 31:
+				fmt.Print(beep)
+			default:
+				if pos == len(line) && !s.multiLineMode && countGlyphs(p)+countGlyphs(line) < s.columns-1 {
+					line = append(line, v)
+					fmt.Printf("%c", v)
+					pos++
+				} else {
+					line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
+					pos++
+					s.refresh(p, line, pos)
+				}
+			}
+		case action:
+			switch v {
+			case del:
+				if pos >= len(line) {
+					fmt.Print(beep)
+				} else {
+					n := len(getPrefixGlyphs(line[pos:], 1))
+					line = append(line[:pos], line[pos+n:]...)
+				}
+			case left:
+				if pos > 0 {
+					pos -= len(getSuffixGlyphs(line[:pos], 1))
+				} else {
+					fmt.Print(beep)
+				}
+			case wordLeft, altB:
+				if pos > 0 {
+					var spaceHere, spaceLeft, leftKnown bool
+					for {
+						pos--
+						if pos == 0 {
+							break
+						}
+						if leftKnown {
+							spaceHere = spaceLeft
+						} else {
+							spaceHere = unicode.IsSpace(line[pos])
+						}
+						spaceLeft, leftKnown = unicode.IsSpace(line[pos-1]), true
+						if !spaceHere && spaceLeft {
+							break
+						}
+					}
+				} else {
+					fmt.Print(beep)
+				}
+			case right:
+				if pos < len(line) {
+					pos += len(getPrefixGlyphs(line[pos:], 1))
+				} else {
+					fmt.Print(beep)
+				}
+			case wordRight, altF:
+				if pos < len(line) {
+					var spaceHere, spaceLeft, hereKnown bool
+					for {
+						pos++
+						if pos == len(line) {
+							break
+						}
+						if hereKnown {
+							spaceLeft = spaceHere
+						} else {
+							spaceLeft = unicode.IsSpace(line[pos-1])
+						}
+						spaceHere, hereKnown = unicode.IsSpace(line[pos]), true
+						if spaceHere && !spaceLeft {
+							break
+						}
+					}
+				} else {
+					fmt.Print(beep)
+				}
+			case up:
+				historyAction = true
+				if historyPos > 0 {
+					if historyPos == len(prefixHistory) {
+						historyEnd = string(line)
+					}
+					historyPos--
+					line = []rune(prefixHistory[historyPos])
+					pos = len(line)
+				} else {
+					fmt.Print(beep)
+				}
+			case down:
+				historyAction = true
+				if historyPos < len(prefixHistory) {
+					historyPos++
+					if historyPos == len(prefixHistory) {
+						line = []rune(historyEnd)
+					} else {
+						line = []rune(prefixHistory[historyPos])
+					}
+					pos = len(line)
+				} else {
+					fmt.Print(beep)
+				}
+			case home: // Start of line
+				pos = 0
+			case end: // End of line
+				pos = len(line)
+			case winch: // Window change
+				if s.multiLineMode {
+					if s.maxRows-s.cursorRows > 0 {
+						s.moveDown(s.maxRows - s.cursorRows)
+					}
+					for i := 0; i < s.maxRows-1; i++ {
+						s.cursorPos(0)
+						s.eraseLine()
+						s.moveUp(1)
+					}
+					s.maxRows = 1
+					s.cursorRows = 1
+				}
+			}
+			s.refresh(p, line, pos)
+		}
+		if !historyAction {
+			prefixHistory = s.getHistoryByPrefix(string(line))
+			historyPos = len(prefixHistory)
+		}
+		if killAction > 0 {
+			killAction--
+		}
+	}
+	return string(line), nil
+}
+
+// PasswordPrompt displays p, and then waits for user input. The input typed by
+// the user is not displayed in the terminal.
+func (s *State) PasswordPrompt(prompt string) (string, error) {
+	if !s.terminalSupported {
+		return "", errors.New("liner: function not supported in this terminal")
+	}
+	if s.inputRedirected {
+		return s.promptUnsupported(prompt)
+	}
+	if s.outputRedirected {
+		return "", ErrNotTerminalOutput
+	}
+
+	defer s.stopPrompt()
+
+restart:
+	s.startPrompt()
+	s.getColumns()
+
+	fmt.Print(prompt)
+	p := []rune(prompt)
+	var line []rune
+	pos := 0
+
+mainLoop:
+	for {
+		next, err := s.readNext()
+		if err != nil {
+			if s.shouldRestart != nil && s.shouldRestart(err) {
+				goto restart
+			}
+			return "", err
+		}
+
+		switch v := next.(type) {
+		case rune:
+			switch v {
+			case cr, lf:
+				if s.multiLineMode {
+					s.resetMultiLine(p, line, pos)
+				}
+				fmt.Println()
+				break mainLoop
+			case ctrlD: // del
+				if pos == 0 && len(line) == 0 {
+					// exit
+					return "", io.EOF
+				}
+
+				// ctrlD is a potential EOF, so the rune reader shuts down.
+				// Therefore, if it isn't actually an EOF, we must re-startPrompt.
+				s.restartPrompt()
+			case ctrlL: // clear screen
+				s.eraseScreen()
+				s.refresh(p, []rune{}, 0)
+			case ctrlH, bs: // Backspace
+				if pos <= 0 {
+					fmt.Print(beep)
+				} else {
+					n := len(getSuffixGlyphs(line[:pos], 1))
+					line = append(line[:pos-n], line[pos:]...)
+					pos -= n
+				}
+			case ctrlC:
+				fmt.Println("^C")
+				if s.multiLineMode {
+					s.resetMultiLine(p, line, pos)
+				}
+				if s.ctrlCAborts {
+					return "", ErrPromptAborted
+				}
+				line = line[:0]
+				pos = 0
+				fmt.Print(prompt)
+				s.restartPrompt()
+			// Unused keys
+			case esc, tab, ctrlA, ctrlB, ctrlE, ctrlF, ctrlG, ctrlK, ctrlN, ctrlO, ctrlP, ctrlQ, ctrlR, ctrlS,
+				ctrlT, ctrlU, ctrlV, ctrlW, ctrlX, ctrlY, ctrlZ:
+				fallthrough
+			// Catch unhandled control codes (anything <= 31)
+			case 0, 28, 29, 30, 31:
+				fmt.Print(beep)
+			default:
+				line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
+				pos++
+			}
+		}
+	}
+	return string(line), nil
+}