Index: node_modules/postcss/lib/map-generator.js
===================================================================
--- node_modules/postcss/lib/map-generator.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss/lib/map-generator.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,368 @@
+'use strict'
+
+let { dirname, relative, resolve, sep } = require('path')
+let { SourceMapConsumer, SourceMapGenerator } = require('source-map-js')
+let { pathToFileURL } = require('url')
+
+let Input = require('./input')
+
+let sourceMapAvailable = Boolean(SourceMapConsumer && SourceMapGenerator)
+let pathAvailable = Boolean(dirname && resolve && relative && sep)
+
+class MapGenerator {
+  constructor(stringify, root, opts, cssString) {
+    this.stringify = stringify
+    this.mapOpts = opts.map || {}
+    this.root = root
+    this.opts = opts
+    this.css = cssString
+    this.originalCSS = cssString
+    this.usesFileUrls = !this.mapOpts.from && this.mapOpts.absolute
+
+    this.memoizedFileURLs = new Map()
+    this.memoizedPaths = new Map()
+    this.memoizedURLs = new Map()
+  }
+
+  addAnnotation() {
+    let content
+
+    if (this.isInline()) {
+      content =
+        'data:application/json;base64,' + this.toBase64(this.map.toString())
+    } else if (typeof this.mapOpts.annotation === 'string') {
+      content = this.mapOpts.annotation
+    } else if (typeof this.mapOpts.annotation === 'function') {
+      content = this.mapOpts.annotation(this.opts.to, this.root)
+    } else {
+      content = this.outputFile() + '.map'
+    }
+    let eol = '\n'
+    if (this.css.includes('\r\n')) eol = '\r\n'
+
+    this.css += eol + '/*# sourceMappingURL=' + content + ' */'
+  }
+
+  applyPrevMaps() {
+    for (let prev of this.previous()) {
+      let from = this.toUrl(this.path(prev.file))
+      let root = prev.root || dirname(prev.file)
+      let map
+
+      if (this.mapOpts.sourcesContent === false) {
+        map = new SourceMapConsumer(prev.text)
+        if (map.sourcesContent) {
+          map.sourcesContent = null
+        }
+      } else {
+        map = prev.consumer()
+      }
+
+      this.map.applySourceMap(map, from, this.toUrl(this.path(root)))
+    }
+  }
+
+  clearAnnotation() {
+    if (this.mapOpts.annotation === false) return
+
+    if (this.root) {
+      let node
+      for (let i = this.root.nodes.length - 1; i >= 0; i--) {
+        node = this.root.nodes[i]
+        if (node.type !== 'comment') continue
+        if (node.text.startsWith('# sourceMappingURL=')) {
+          this.root.removeChild(i)
+        }
+      }
+    } else if (this.css) {
+      this.css = this.css.replace(/\n*\/\*#[\S\s]*?\*\/$/gm, '')
+    }
+  }
+
+  generate() {
+    this.clearAnnotation()
+    if (pathAvailable && sourceMapAvailable && this.isMap()) {
+      return this.generateMap()
+    } else {
+      let result = ''
+      this.stringify(this.root, i => {
+        result += i
+      })
+      return [result]
+    }
+  }
+
+  generateMap() {
+    if (this.root) {
+      this.generateString()
+    } else if (this.previous().length === 1) {
+      let prev = this.previous()[0].consumer()
+      prev.file = this.outputFile()
+      this.map = SourceMapGenerator.fromSourceMap(prev, {
+        ignoreInvalidMapping: true
+      })
+    } else {
+      this.map = new SourceMapGenerator({
+        file: this.outputFile(),
+        ignoreInvalidMapping: true
+      })
+      this.map.addMapping({
+        generated: { column: 0, line: 1 },
+        original: { column: 0, line: 1 },
+        source: this.opts.from
+          ? this.toUrl(this.path(this.opts.from))
+          : '<no source>'
+      })
+    }
+
+    if (this.isSourcesContent()) this.setSourcesContent()
+    if (this.root && this.previous().length > 0) this.applyPrevMaps()
+    if (this.isAnnotation()) this.addAnnotation()
+
+    if (this.isInline()) {
+      return [this.css]
+    } else {
+      return [this.css, this.map]
+    }
+  }
+
+  generateString() {
+    this.css = ''
+    this.map = new SourceMapGenerator({
+      file: this.outputFile(),
+      ignoreInvalidMapping: true
+    })
+
+    let line = 1
+    let column = 1
+
+    let noSource = '<no source>'
+    let mapping = {
+      generated: { column: 0, line: 0 },
+      original: { column: 0, line: 0 },
+      source: ''
+    }
+
+    let last, lines
+    this.stringify(this.root, (str, node, type) => {
+      this.css += str
+
+      if (node && type !== 'end') {
+        mapping.generated.line = line
+        mapping.generated.column = column - 1
+        if (node.source && node.source.start) {
+          mapping.source = this.sourcePath(node)
+          mapping.original.line = node.source.start.line
+          mapping.original.column = node.source.start.column - 1
+          this.map.addMapping(mapping)
+        } else {
+          mapping.source = noSource
+          mapping.original.line = 1
+          mapping.original.column = 0
+          this.map.addMapping(mapping)
+        }
+      }
+
+      lines = str.match(/\n/g)
+      if (lines) {
+        line += lines.length
+        last = str.lastIndexOf('\n')
+        column = str.length - last
+      } else {
+        column += str.length
+      }
+
+      if (node && type !== 'start') {
+        let p = node.parent || { raws: {} }
+        let childless =
+          node.type === 'decl' || (node.type === 'atrule' && !node.nodes)
+        if (!childless || node !== p.last || p.raws.semicolon) {
+          if (node.source && node.source.end) {
+            mapping.source = this.sourcePath(node)
+            mapping.original.line = node.source.end.line
+            mapping.original.column = node.source.end.column - 1
+            mapping.generated.line = line
+            mapping.generated.column = column - 2
+            this.map.addMapping(mapping)
+          } else {
+            mapping.source = noSource
+            mapping.original.line = 1
+            mapping.original.column = 0
+            mapping.generated.line = line
+            mapping.generated.column = column - 1
+            this.map.addMapping(mapping)
+          }
+        }
+      }
+    })
+  }
+
+  isAnnotation() {
+    if (this.isInline()) {
+      return true
+    }
+    if (typeof this.mapOpts.annotation !== 'undefined') {
+      return this.mapOpts.annotation
+    }
+    if (this.previous().length) {
+      return this.previous().some(i => i.annotation)
+    }
+    return true
+  }
+
+  isInline() {
+    if (typeof this.mapOpts.inline !== 'undefined') {
+      return this.mapOpts.inline
+    }
+
+    let annotation = this.mapOpts.annotation
+    if (typeof annotation !== 'undefined' && annotation !== true) {
+      return false
+    }
+
+    if (this.previous().length) {
+      return this.previous().some(i => i.inline)
+    }
+    return true
+  }
+
+  isMap() {
+    if (typeof this.opts.map !== 'undefined') {
+      return !!this.opts.map
+    }
+    return this.previous().length > 0
+  }
+
+  isSourcesContent() {
+    if (typeof this.mapOpts.sourcesContent !== 'undefined') {
+      return this.mapOpts.sourcesContent
+    }
+    if (this.previous().length) {
+      return this.previous().some(i => i.withContent())
+    }
+    return true
+  }
+
+  outputFile() {
+    if (this.opts.to) {
+      return this.path(this.opts.to)
+    } else if (this.opts.from) {
+      return this.path(this.opts.from)
+    } else {
+      return 'to.css'
+    }
+  }
+
+  path(file) {
+    if (this.mapOpts.absolute) return file
+    if (file.charCodeAt(0) === 60 /* `<` */) return file
+    if (/^\w+:\/\//.test(file)) return file
+    let cached = this.memoizedPaths.get(file)
+    if (cached) return cached
+
+    let from = this.opts.to ? dirname(this.opts.to) : '.'
+
+    if (typeof this.mapOpts.annotation === 'string') {
+      from = dirname(resolve(from, this.mapOpts.annotation))
+    }
+
+    let path = relative(from, file)
+    this.memoizedPaths.set(file, path)
+
+    return path
+  }
+
+  previous() {
+    if (!this.previousMaps) {
+      this.previousMaps = []
+      if (this.root) {
+        this.root.walk(node => {
+          if (node.source && node.source.input.map) {
+            let map = node.source.input.map
+            if (!this.previousMaps.includes(map)) {
+              this.previousMaps.push(map)
+            }
+          }
+        })
+      } else {
+        let input = new Input(this.originalCSS, this.opts)
+        if (input.map) this.previousMaps.push(input.map)
+      }
+    }
+
+    return this.previousMaps
+  }
+
+  setSourcesContent() {
+    let already = {}
+    if (this.root) {
+      this.root.walk(node => {
+        if (node.source) {
+          let from = node.source.input.from
+          if (from && !already[from]) {
+            already[from] = true
+            let fromUrl = this.usesFileUrls
+              ? this.toFileUrl(from)
+              : this.toUrl(this.path(from))
+            this.map.setSourceContent(fromUrl, node.source.input.css)
+          }
+        }
+      })
+    } else if (this.css) {
+      let from = this.opts.from
+        ? this.toUrl(this.path(this.opts.from))
+        : '<no source>'
+      this.map.setSourceContent(from, this.css)
+    }
+  }
+
+  sourcePath(node) {
+    if (this.mapOpts.from) {
+      return this.toUrl(this.mapOpts.from)
+    } else if (this.usesFileUrls) {
+      return this.toFileUrl(node.source.input.from)
+    } else {
+      return this.toUrl(this.path(node.source.input.from))
+    }
+  }
+
+  toBase64(str) {
+    if (Buffer) {
+      return Buffer.from(str).toString('base64')
+    } else {
+      return window.btoa(unescape(encodeURIComponent(str)))
+    }
+  }
+
+  toFileUrl(path) {
+    let cached = this.memoizedFileURLs.get(path)
+    if (cached) return cached
+
+    if (pathToFileURL) {
+      let fileURL = pathToFileURL(path).toString()
+      this.memoizedFileURLs.set(path, fileURL)
+
+      return fileURL
+    } else {
+      throw new Error(
+        '`map.absolute` option is not available in this PostCSS build'
+      )
+    }
+  }
+
+  toUrl(path) {
+    let cached = this.memoizedURLs.get(path)
+    if (cached) return cached
+
+    if (sep === '\\') {
+      path = path.replace(/\\/g, '/')
+    }
+
+    let url = encodeURI(path).replace(/[#?]/g, encodeURIComponent)
+    this.memoizedURLs.set(path, url)
+
+    return url
+  }
+}
+
+module.exports = MapGenerator