Index: node_modules/autoprefixer/lib/hacks/flex.js
===================================================================
--- node_modules/autoprefixer/lib/hacks/flex.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/autoprefixer/lib/hacks/flex.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,54 @@
+let list = require('postcss').list
+
+let Declaration = require('../declaration')
+let flexSpec = require('./flex-spec')
+
+class Flex extends Declaration {
+  /**
+   * Return property name by final spec
+   */
+  normalize() {
+    return 'flex'
+  }
+
+  /**
+   * Change property name for 2009 spec
+   */
+  prefixed(prop, prefix) {
+    let spec
+    ;[spec, prefix] = flexSpec(prefix)
+    if (spec === 2009) {
+      return prefix + 'box-flex'
+    }
+    return super.prefixed(prop, prefix)
+  }
+
+  /**
+   * Spec 2009 supports only first argument
+   * Spec 2012 disallows unitless basis
+   */
+  set(decl, prefix) {
+    let spec = flexSpec(prefix)[0]
+    if (spec === 2009) {
+      decl.value = list.space(decl.value)[0]
+      decl.value = Flex.oldValues[decl.value] || decl.value
+      return super.set(decl, prefix)
+    }
+    if (spec === 2012) {
+      let components = list.space(decl.value)
+      if (components.length === 3 && components[2] === '0') {
+        decl.value = components.slice(0, 2).concat('0px').join(' ')
+      }
+    }
+    return super.set(decl, prefix)
+  }
+}
+
+Flex.names = ['flex', 'box-flex']
+
+Flex.oldValues = {
+  auto: '1',
+  none: '0'
+}
+
+module.exports = Flex