Transform : into f03a on Windows

Also, strip Windows-absolute paths from tarballs, even on Unix (same as
bsdtar and gnutar do), and be careful not to pass the drive letter to
the winchars.encode function so that the : there isn't converted.

Close isaacs#111

Author: isaacs

README.md

@@ -657,7 +657,7 @@ It has the following fields:
 - `strict` Treat warnings as crash-worthy errors.  Default false.
 - `win32` True if on a windows platform.  Causes behavior where paths
   replace `\` with `/` and filenames containing the windows-compatible
-  forms of `<|>?` characters are converted to actual `<|>?` characters
+  forms of `<|>?:` characters are converted to actual `<|>?:` characters
   in the archive.
 - `noPax` Suppress pax extended headers.  Note that this means that
   long paths and linkpaths will be truncated, and large or negative

lib/unpack.js

@@ -7,7 +7,7 @@ const fs = require('fs')
 const path = require('path')
 const mkdir = require('./mkdir.js')
 const mkdirSync = mkdir.sync
-const winchars = require('./winchars.js')
+const wc = require('./winchars.js')
 
 const ONENTRY = Symbol('onEntry')
 const CHECKFS = Symbol('checkFs')
@@ -98,15 +98,22 @@ class Unpack extends Parser {
         this.warn('path contains \'..\'', p)
         return false
       }
-      if (path.isAbsolute(p)) {
-        const parsed = path.parse(p)
+
+      // absolutes on posix are also absolutes on win32
+      // so we only need to test this one to get both
+      if (path.win32.isAbsolute(p)) {
+        const parsed = path.win32.parse(p)
         this.warn('stripping ' + parsed.root + ' from absolute path', p)
         entry.path = p.substr(parsed.root.length)
       }
     }
 
-    if (this.win32)
-      entry.path = winchars.encode(entry.path)
+    // only encode : chars that aren't drive letter indicators
+    if (this.win32) {
+      const parsed = path.win32.parse(entry.path)
+      entry.path = parsed.root === '' ? wc.encode(entry.path)
+        : parsed.root + wc.encode(entry.path.substr(parsed.root.length))
+    }
 
     if (path.isAbsolute(entry.path))
       entry.absolute = entry.path

lib/winchars.js

@@ -7,7 +7,8 @@ const raw = [
   '|',
   '<',
   '>',
-  '?'
+  '?',
+  ':'
 ]
 
 const win = raw.map(char =>

lib/write-entry.js

@@ -47,8 +47,10 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
     if (typeof opt.onwarn === 'function')
       this.on('warn', opt.onwarn)
 
-    if (path.isAbsolute(p) && !this.preservePaths) {
-      const parsed = path.parse(p)
+    if (!this.preservePaths && path.win32.isAbsolute(p)) {
+      // absolutes on posix are also absolutes on win32
+      // so we only need to test this one to get both
+      const parsed = path.win32.parse(p)
       this.warn('stripping ' + parsed.root + ' from absolute path', p)
       this.path = p.substr(parsed.root.length)
     }

test/unpack.js

@@ -1622,11 +1622,11 @@ t.test('unpack when dir is not writable', t => {
 t.test('transmute chars on windows', t => {
   const data = makeTar([
     {
-      path: '<|>?.txt',
-      size: 4,
+      path: '<|>?:.txt',
+      size: 5,
       type: 'File'
     },
-    '<|>?',
+    '<|>?:',
     '',
     ''
   ])
@@ -1635,12 +1635,13 @@ t.test('transmute chars on windows', t => {
   t.beforeEach(cb => mkdirp(dir, cb))
   t.afterEach(cb => rimraf(dir, cb))
 
-  const uglyName = new Buffer('ef80bcef81bcef80beef80bf2e747874', 'hex').toString()
+  const hex = 'ef80bcef81bcef80beef80bfef80ba2e747874'
+  const uglyName = new Buffer(hex, 'hex').toString()
   const ugly = path.resolve(dir, uglyName)
 
   const check = t => {
     t.same(fs.readdirSync(dir), [ uglyName ])
-    t.equal(fs.readFileSync(ugly, 'utf8'), '<|>?')
+    t.equal(fs.readFileSync(ugly, 'utf8'), '<|>?:')
     t.end()
   }
 
@@ -1664,3 +1665,35 @@ t.test('transmute chars on windows', t => {
 
   t.end()
 })
+
+t.test('safely transmute chars on windows with absolutes', t => {
+  // don't actually make the directory
+  const poop = new Error('poop')
+  t.teardown(mutateFS.fail('mkdir', poop))
+
+  const data = makeTar([
+    {
+      path: 'c:/x/y/z/<|>?:.txt',
+      size: 5,
+      type: 'File'
+    },
+    '<|>?:',
+    '',
+    ''
+  ])
+
+  const hex = 'ef80bcef81bcef80beef80bfef80ba2e747874'
+  const uglyName = new Buffer(hex, 'hex').toString()
+  const uglyPath = 'c:/x/y/z/' + uglyName
+
+  const u = new Unpack({
+    win32: true,
+    preservePaths: true
+  })
+  u.on('entry', entry => {
+    t.equal(entry.path, uglyPath)
+    t.end()
+  })
+
+  u.end(data)
+})