readline: properly handle 0-width characters

TimothyGu · addaleax · commit b4b27b2edd42 · 2017-07-18T19:57:11.000+02:00
PR-URL: #13918 Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/lib/readline.js b/lib/readline.js
@@ -670,13 +670,14 @@ Interface.prototype._getDisplayPos = function(str){
 row += 1;
 continue;
 }
- if (isFullWidthCodePoint(code)){
+ const width = getStringWidth(code);
+ if (width === 0 || width === 1){
+ offset += width;
+ } else{// width === 2
 if ((offset + 1) % col === 0){
 offset++;
 }
 offset += 2;
- } else{
- offset++;
 }
 }
 var cols = offset % col;
diff --git a/test/parallel/test-readline-position.js b/test/parallel/test-readline-position.js
@@ -0,0 +1,31 @@
+'use strict';
+require('../common');
+const{PassThrough } = require('stream');
+const readline = require('readline');
+const assert = require('assert');
+
+const ctrlU ={ctrl: true, name: 'u' };
+
+{
+ const input = new PassThrough();
+ const rl = readline.createInterface({
+ terminal: true,
+ input: input,
+ prompt: ''
+ });
+
+ for (const [cursor, string] of [
+ [1, 'a'],
+ [2, 'ab'],
+ [2, '丁'],
+ [0, '\u0301'], // COMBINING ACUTE ACCENT
+ [1, 'a\u0301'], // á
+ [0, '\u20DD'], // COMBINING ENCLOSING CIRCLE
+ [2, 'a\u20DDb'], // a⃝b
+ [0, '\u200E'] // LEFT-TO-RIGHT MARK
+ ]){
+ rl.write(string);
+ assert.strictEqual(rl._getCursorPos().cols, cursor);
+ rl.write(null, ctrlU);
+ }
+}

Original file line number	Diff line number	Diff line change
`@@ -670,13 +670,14 @@ Interface.prototype._getDisplayPos = function(str){`
`670`	`670`	`row+=1;`
`671`	`671`	`continue;`
`672`	`672`	`}`
`673`		`-if(isFullWidthCodePoint(code)){`
	`673`	`+constwidth=getStringWidth(code);`
	`674`	`+if(width===0\|\|width===1){`
	`675`	`+offset+=width;`
	`676`	`+}else{// width === 2`
`674`	`677`	`if((offset+1)%col===0){`
`675`	`678`	`offset++;`
`676`	`679`	`}`
`677`	`680`	`offset+=2;`
`678`		`-}else{`
`679`		`-offset++;`
`680`	`681`	`}`
`681`	`682`	`}`
`682`	`683`	`varcols=offset%col;`
-Original file line number
+Diff line change
@@ @@ -0,0 +1,31 @@ @@
 +'use strict';
 +require('../common');
 +const{ PassThrough }=require('stream');
 +constreadline=require('readline');
 +constassert=require('assert');
++
 +constctrlU={ctrl: true,name: 'u'};
++
 +{
 +constinput=newPassThrough();
 +constrl=readline.createInterface({
 +terminal: true,
 +input: input,
 +prompt: ''
 +});
++
 +for(const[cursor,string]of[
 +[1,'a'],
 +[2,'ab'],
 +[2,'丁'],
 +[0,'\u0301'],// COMBINING ACUTE ACCENT
 +[1,'a\u0301'],// á
 +[0,'\u20DD'],// COMBINING ENCLOSING CIRCLE
 +[2,'a\u20DDb'],// a⃝b
 +[0,'\u200E']// LEFT-TO-RIGHT MARK
 +]){
 +rl.write(string);
 +assert.strictEqual(rl._getCursorPos().cols,cursor);
 +rl.write(null,ctrlU);
 +}
 +}