path: fix normalize on directories with two dots

PR-URL: https://github.com/nodejs/node/pull/14107
Fixes: https://github.com/nodejs/node/issues/14105
Reviewed-By: Refael Ackermann <refack@gmail.com>

lib/path.js

@@ -35,6 +35,7 @@ function normalizeStringWin32(path, allowAboveRoot) {
   var lastSlash = -1;
   var dots = 0;
   var code;
+  var isAboveRoot = false;
   for (var i = 0; i <= path.length; ++i) {
     if (i < path.length)
       code = path.charCodeAt(i);
@@ -46,7 +47,7 @@ function normalizeStringWin32(path, allowAboveRoot) {
       if (lastSlash === i - 1 || dots === 1) {
         // NOOP
       } else if (lastSlash !== i - 1 && dots === 2) {
-        if (res.length < 2 ||
+        if (res.length < 2 || !isAboveRoot ||
             res.charCodeAt(res.length - 1) !== 46/*.*/ ||
             res.charCodeAt(res.length - 2) !== 46/*.*/) {
           if (res.length > 2) {
@@ -63,12 +64,14 @@ function normalizeStringWin32(path, allowAboveRoot) {
                 res = res.slice(0, j);
               lastSlash = i;
               dots = 0;
+              isAboveRoot = false;
               continue;
             }
           } else if (res.length === 2 || res.length === 1) {
             res = '';
             lastSlash = i;
             dots = 0;
+            isAboveRoot = false;
             continue;
           }
         }
@@ -77,12 +80,14 @@ function normalizeStringWin32(path, allowAboveRoot) {
             res += '\\..';
           else
             res = '..';
+          isAboveRoot = true;
         }
       } else {
         if (res.length > 0)
           res += '\\' + path.slice(lastSlash + 1, i);
         else
           res = path.slice(lastSlash + 1, i);
+        isAboveRoot = false;
       }
       lastSlash = i;
       dots = 0;
@@ -101,6 +106,7 @@ function normalizeStringPosix(path, allowAboveRoot) {
   var lastSlash = -1;
   var dots = 0;
   var code;
+  var isAboveRoot = false;
   for (var i = 0; i <= path.length; ++i) {
     if (i < path.length)
       code = path.charCodeAt(i);
@@ -112,7 +118,7 @@ function normalizeStringPosix(path, allowAboveRoot) {
       if (lastSlash === i - 1 || dots === 1) {
         // NOOP
       } else if (lastSlash !== i - 1 && dots === 2) {
-        if (res.length < 2 ||
+        if (res.length < 2 || !isAboveRoot ||
             res.charCodeAt(res.length - 1) !== 46/*.*/ ||
             res.charCodeAt(res.length - 2) !== 46/*.*/) {
           if (res.length > 2) {
@@ -129,12 +135,14 @@ function normalizeStringPosix(path, allowAboveRoot) {
                 res = res.slice(0, j);
               lastSlash = i;
               dots = 0;
+              isAboveRoot = false;
               continue;
             }
           } else if (res.length === 2 || res.length === 1) {
             res = '';
             lastSlash = i;
             dots = 0;
+            isAboveRoot = false;
             continue;
           }
         }
@@ -143,12 +151,14 @@ function normalizeStringPosix(path, allowAboveRoot) {
             res += '/..';
           else
             res = '..';
+          isAboveRoot = true;
         }
       } else {
         if (res.length > 0)
           res += '/' + path.slice(lastSlash + 1, i);
         else
           res = path.slice(lastSlash + 1, i);
+        isAboveRoot = false;
       }
       lastSlash = i;
       dots = 0;

test/parallel/test-path.js

@@ -432,6 +432,11 @@ assert.strictEqual(path.win32.normalize('C:..\\..\\abc\\..\\def'),
                    'C:..\\..\\def');
 assert.strictEqual(path.win32.normalize('C:\\.'), 'C:\\');
 assert.strictEqual(path.win32.normalize('file:stream'), 'file:stream');
+assert.strictEqual(path.win32.normalize('bar\\foo..\\..\\'), 'bar\\');
+assert.strictEqual(path.win32.normalize('bar\\foo..\\..'), 'bar');
+assert.strictEqual(path.win32.normalize('bar\\foo..\\..\\baz'), 'bar\\baz');
+assert.strictEqual(path.win32.normalize('bar\\foo..\\'), 'bar\\foo..\\');
+assert.strictEqual(path.win32.normalize('bar\\foo..'), 'bar\\foo..');
 
 assert.strictEqual(path.posix.normalize('./fixtures///b/../b/c.js'),
                    'fixtures/b/c.js');
@@ -441,6 +446,11 @@ assert.strictEqual(path.posix.normalize('a//b//./c'), 'a/b/c');
 assert.strictEqual(path.posix.normalize('a//b//.'), 'a/b');
 assert.strictEqual(path.posix.normalize('/a/b/c/../../../x/y/z'), '/x/y/z');
 assert.strictEqual(path.posix.normalize('///..//./foo/.//bar'), '/foo/bar');
+assert.strictEqual(path.posix.normalize('bar/foo../../'), 'bar/');
+assert.strictEqual(path.posix.normalize('bar/foo../..'), 'bar');
+assert.strictEqual(path.posix.normalize('bar/foo../../baz'), 'bar/baz');
+assert.strictEqual(path.posix.normalize('bar/foo../'), 'bar/foo../');
+assert.strictEqual(path.posix.normalize('bar/foo..'), 'bar/foo..');
 
 
 // path.resolve tests