fix: detectLanguage function (#3966)

maple3142 · haoqunjiang · commit eac03255c9f3 · 2019-05-25T20:41:07.000+08:00
(cherry picked from commit 206803c)
diff --git a/packages/@vue/cli-ui/src/i18n.js b/packages/@vue/cli-ui/src/i18n.js
@@ -15,7 +15,7 @@ function detectLanguage () {
     const lang = (window.navigator.languages && window.navigator.languages[0]) ||
       window.navigator.language ||
       window.navigator.userLanguage
-    return [ lang, lang.toLowerCase(), lang.substr(0, 2) ]
+    return [ lang, lang.toLowerCase(), lang.substr(0, 2) ].map(lang => lang.replace('-', '_'))
   } catch (e) {
     return undefined
   }

Original file line number	Diff line number	Diff line change
`@@ -15,7 +15,7 @@ function detectLanguage () {`
`15`	`15`	`const lang = (window.navigator.languages && window.navigator.languages[0]) \|\|`
`16`	`16`	`window.navigator.language \|\|`
`17`	`17`	`window.navigator.userLanguage`
`18`		`- return [ lang, lang.toLowerCase(), lang.substr(0, 2) ]`
	`18`	`+ return [ lang, lang.toLowerCase(), lang.substr(0, 2) ].map(lang => lang.replace('-', '_'))`
`19`	`19`	`} catch (e) {`
`20`	`20`	`return undefined`
`21`	`21`	`}`