From e20ff77be902f1a8e4bbc6b3fa44db778fa68a8b Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Sat, 14 May 2016 15:24:34 -0700
Subject: [PATCH 01/12] child_process: measure buffer length in bytes

This change fixes a known issue where `maxBuffer` limits by characters
rather than bytes. Benchmark added to confirm no performance regression
occurs with this change.

Fixes: https://github.com/nodejs/node/issues/1901
---
 .../child-process-exec-stdout.js              | 29 +++++++++++++++++++
 benchmark/child_process/child-process-read.js | 18 ++++++------
 lib/child_process.js                          | 14 +++------
 .../test-child-process-maxBuffer-stderr.js    | 15 ++++++++++
 .../test-child-process-maxBuffer-stdout.js}   |  3 +-
 5 files changed, 58 insertions(+), 21 deletions(-)
 create mode 100644 benchmark/child_process/child-process-exec-stdout.js
 create mode 100644 test/parallel/test-child-process-maxBuffer-stderr.js
 rename test/{known_issues/test-child-process-max-buffer.js => parallel/test-child-process-maxBuffer-stdout.js} (75%)

diff --git a/benchmark/child_process/child-process-exec-stdout.js b/benchmark/child_process/child-process-exec-stdout.js
new file mode 100644
index 00000000000000..57230341cd767b
--- /dev/null
+++ b/benchmark/child_process/child-process-exec-stdout.js
@@ -0,0 +1,29 @@
+'use strict';
+const common = require('../common.js');
+const bench = common.createBenchmark(main, {
+  len: [64, 256, 1024, 4096, 32768],
+  dur: [5]
+});
+
+const exec = require('child_process').exec;
+function main(conf) {
+  bench.start();
+
+  const dur = +conf.dur;
+  const len = +conf.len;
+
+  const msg = '"' + Array(len).join('.') + '"';
+  const options = {'stdio': ['ignore', 'pipe', 'ignore']};
+  // NOTE: Command below assumes bash shell.
+  const child = exec(`while\n  echo ${msg}\ndo :; done\n`, options);
+
+  var bytes = 0;
+  child.stdout.on('data', function(msg) {
+    bytes += msg.length;
+  });
+
+  setTimeout(function() {
+    child.kill();
+    bench.end(bytes);
+  }, dur * 1000);
+}
diff --git a/benchmark/child_process/child-process-read.js b/benchmark/child_process/child-process-read.js
index c1a7474aae32c1..33c268390fd5c3 100644
--- a/benchmark/child_process/child-process-read.js
+++ b/benchmark/child_process/child-process-read.js
@@ -1,20 +1,20 @@
 'use strict';
-var common = require('../common.js');
-var bench = common.createBenchmark(main, {
+const common = require('../common.js');
+const bench = common.createBenchmark(main, {
   len: [64, 256, 1024, 4096, 32768],
   dur: [5]
 });
 
-var spawn = require('child_process').spawn;
+const spawn = require('child_process').spawn;
 function main(conf) {
   bench.start();
 
-  var dur = +conf.dur;
-  var len = +conf.len;
+  const dur = +conf.dur;
+  const len = +conf.len;
 
-  var msg = '"' + Array(len).join('.') + '"';
-  var options = { 'stdio': ['ignore', 'ipc', 'ignore'] };
-  var child = spawn('yes', [msg], options);
+  const msg = '"' + Array(len).join('.') + '"';
+  const options = {'stdio': ['ignore', 'ipc', 'ignore']};
+  const child = spawn('yes', [msg], options);
 
   var bytes = 0;
   child.on('message', function(msg) {
@@ -23,7 +23,7 @@ function main(conf) {
 
   setTimeout(function() {
     child.kill();
-    var gbits = (bytes * 8) / (1024 * 1024 * 1024);
+    const gbits = (bytes * 8) / (1024 * 1024 * 1024);
     bench.end(gbits);
   }, dur * 1000);
 }
diff --git a/lib/child_process.js b/lib/child_process.js
index 2d2e23bbf11672..97d9027d24f74a 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -245,11 +245,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
   }
 
   if (child.stdout) {
-    if (encoding)
-      child.stdout.setEncoding(encoding);
-
     child.stdout.addListener('data', function(chunk) {
-      stdoutLen += chunk.length;
+      stdoutLen += chunk.byteLength;
 
       if (stdoutLen > options.maxBuffer) {
         ex = new Error('stdout maxBuffer exceeded');
@@ -258,17 +255,14 @@ exports.execFile = function(file /*, args, options, callback*/) {
         if (!encoding)
           _stdout.push(chunk);
         else
-          _stdout += chunk;
+          _stdout += chunk.toString(encoding);
       }
     });
   }
 
   if (child.stderr) {
-    if (encoding)
-      child.stderr.setEncoding(encoding);
-
     child.stderr.addListener('data', function(chunk) {
-      stderrLen += chunk.length;
+      stderrLen += chunk.byteLength;
 
       if (stderrLen > options.maxBuffer) {
         ex = new Error('stderr maxBuffer exceeded');
@@ -277,7 +271,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
         if (!encoding)
           _stderr.push(chunk);
         else
-          _stderr += chunk;
+          _stderr += chunk.toString(encoding);
       }
     });
   }
diff --git a/test/parallel/test-child-process-maxBuffer-stderr.js b/test/parallel/test-child-process-maxBuffer-stderr.js
new file mode 100644
index 00000000000000..ecaea8b152a0ca
--- /dev/null
+++ b/test/parallel/test-child-process-maxBuffer-stderr.js
@@ -0,0 +1,15 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const cp = require('child_process');
+const unicode = '中文测试'; // Length = 4, Byte length = 13
+
+if (process.argv[2] === 'child') {
+  console.error(unicode);
+} else {
+  const cmd = `${process.execPath} ${__filename} child`;
+
+  cp.exec(cmd, {maxBuffer: 10}, common.mustCall((err, stdout, stderr) => {
+    assert.strictEqual(err.message, 'stderr maxBuffer exceeded');
+  }));
+}
diff --git a/test/known_issues/test-child-process-max-buffer.js b/test/parallel/test-child-process-maxBuffer-stdout.js
similarity index 75%
rename from test/known_issues/test-child-process-max-buffer.js
rename to test/parallel/test-child-process-maxBuffer-stdout.js
index 14a344c7062a5a..122dc499f462bf 100644
--- a/test/known_issues/test-child-process-max-buffer.js
+++ b/test/parallel/test-child-process-maxBuffer-stdout.js
@@ -1,5 +1,4 @@
 'use strict';
-// Refs: https://github.com/nodejs/node/issues/1901
 const common = require('../common');
 const assert = require('assert');
 const cp = require('child_process');
@@ -10,7 +9,7 @@ if (process.argv[2] === 'child') {
 } else {
   const cmd = `${process.execPath} ${__filename} child`;
 
-  cp.exec(cmd, { maxBuffer: 10 }, common.mustCall((err, stdout, stderr) => {
+  cp.exec(cmd, {maxBuffer: 10}, common.mustCall((err, stdout, stderr) => {
     assert.strictEqual(err.message, 'stdout maxBuffer exceeded');
   }));
 }

From 3245de672ff8bbf66664d6213460a5d9b8c4769c Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Thu, 19 May 2016 14:51:22 -0700
Subject: [PATCH 02/12] squash: run toString() just once at the end

---
 lib/child_process.js | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 97d9027d24f74a..10250c49718d8c 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -146,15 +146,11 @@ exports.execFile = function(file /*, args, options, callback*/) {
   });
 
   var encoding;
-  var _stdout;
-  var _stderr;
+  var _stdout = [];
+  var _stderr = [];
   if (options.encoding !== 'buffer' && Buffer.isEncoding(options.encoding)) {
     encoding = options.encoding;
-    _stdout = '';
-    _stderr = '';
   } else {
-    _stdout = [];
-    _stderr = [];
     encoding = null;
   }
   var stdoutLen = 0;
@@ -183,8 +179,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
       stdout = Buffer.concat(_stdout);
       stderr = Buffer.concat(_stderr);
     } else {
-      stdout = _stdout;
-      stderr = _stderr;
+      stdout = Buffer.concat(_stdout).toString(encoding);
+      stderr = Buffer.concat(_stderr).toString(encoding);
     }
 
     if (ex) {
@@ -252,10 +248,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
         ex = new Error('stdout maxBuffer exceeded');
         kill();
       } else {
-        if (!encoding)
-          _stdout.push(chunk);
-        else
-          _stdout += chunk.toString(encoding);
+        _stdout.push(chunk);
       }
     });
   }
@@ -268,10 +261,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
         ex = new Error('stderr maxBuffer exceeded');
         kill();
       } else {
-        if (!encoding)
-          _stderr.push(chunk);
-        else
-          _stderr += chunk.toString(encoding);
+        _stderr.push(chunk);
       }
     });
   }

From 7b96b64c6429a696d276c1f5154a5270b0614e26 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Thu, 19 May 2016 21:27:06 -0700
Subject: [PATCH 03/12] squash: optimize Buffer.concat(), handle edge case

---
 lib/child_process.js | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 10250c49718d8c..14dc7d7980eb3c 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -172,15 +172,17 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
     if (!callback) return;
 
-    // merge chunks
-    var stdout;
-    var stderr;
-    if (!encoding) {
-      stdout = Buffer.concat(_stdout);
-      stderr = Buffer.concat(_stderr);
-    } else {
-      stdout = Buffer.concat(_stdout).toString(encoding);
-      stderr = Buffer.concat(_stderr).toString(encoding);
+    // Merge chunks. _stdout/_stderr may contain strings if the calling code
+    // does something like `child.stdout.setEncoding('utf8')`
+    var stdout = (typeof _stdout[0] === 'string') ?
+      _stdout.join('') : Buffer.concat(_stdout, stdoutLen);
+
+    var stderr = (typeof _stderr[0] === 'string') ?
+      _stderr.join('') : Buffer.concat(_stderr, stderrLen);
+
+    if (encoding) {
+      stdout = stdout.toString(encoding);
+      stderr = stderr.toString(encoding);
     }
 
     if (ex) {
@@ -242,10 +244,11 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
   if (child.stdout) {
     child.stdout.addListener('data', function(chunk) {
-      stdoutLen += chunk.byteLength;
+      stdoutLen += (chunk.byteLength || chunk.length);
 
       if (stdoutLen > options.maxBuffer) {
         ex = new Error('stdout maxBuffer exceeded');
+        stdoutLen -= (chunk.byteLength || chunk.length);
         kill();
       } else {
         _stdout.push(chunk);
@@ -255,10 +258,11 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
   if (child.stderr) {
     child.stderr.addListener('data', function(chunk) {
-      stderrLen += chunk.byteLength;
+      stderrLen += (chunk.byteLength || chunk.length);
 
       if (stderrLen > options.maxBuffer) {
         ex = new Error('stderr maxBuffer exceeded');
+        stderrLen -= (chunk.byteLength || chunk.length);
         kill();
       } else {
         _stderr.push(chunk);

From 2b14b6403d7d1b2036152b2831d98806892110d8 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Thu, 19 May 2016 21:35:14 -0700
Subject: [PATCH 04/12] squash: benchmark nits

---
 benchmark/child_process/child-process-exec-stdout.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/benchmark/child_process/child-process-exec-stdout.js b/benchmark/child_process/child-process-exec-stdout.js
index 57230341cd767b..79efb6fadf2aeb 100644
--- a/benchmark/child_process/child-process-exec-stdout.js
+++ b/benchmark/child_process/child-process-exec-stdout.js
@@ -12,7 +12,8 @@ function main(conf) {
   const dur = +conf.dur;
   const len = +conf.len;
 
-  const msg = '"' + Array(len).join('.') + '"';
+  const msg = `"${'.'.repeat(len)}"`;
+  msg.match(/./);
   const options = {'stdio': ['ignore', 'pipe', 'ignore']};
   // NOTE: Command below assumes bash shell.
   const child = exec(`while\n  echo ${msg}\ndo :; done\n`, options);

From 221dec51be082adc743b21219699eeb67f1b9fab Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Thu, 19 May 2016 22:55:47 -0700
Subject: [PATCH 05/12] squash: comment block explaining chunk.length

---
 lib/child_process.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/child_process.js b/lib/child_process.js
index 14dc7d7980eb3c..8d3c4aa13a945e 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -242,6 +242,13 @@ exports.execFile = function(file /*, args, options, callback*/) {
     }, options.timeout);
   }
 
+  // Use chunk.byteLength to get accurate count of bytes, but fall back to
+  // chunk.length in case someone does something like
+  // `child.stdout.setEncoding('utf8')` in userland. That means the bytes may
+  // be under-counted in that situation (if there are characters represented by
+  // more than one byte), but there doesn't seem to be a good fix that wouldn't
+  // be a semver-major (breaking) change.
+
   if (child.stdout) {
     child.stdout.addListener('data', function(chunk) {
       stdoutLen += (chunk.byteLength || chunk.length);

From 425128f3096e5d39b950fc593f3a7278999ca0b1 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Fri, 20 May 2016 13:09:00 -0700
Subject: [PATCH 06/12] squash: get correct length for strings

---
 lib/child_process.js | 46 +++++++++++++++++++++++++++++---------------
 1 file changed, 30 insertions(+), 16 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 8d3c4aa13a945e..c815416df12b0f 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -145,7 +145,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
     windowsVerbatimArguments: !!options.windowsVerbatimArguments
   });
 
-  var encoding;
+  var encoding, stdoutEncoding, stderrEncoding;
   var _stdout = [];
   var _stderr = [];
   if (options.encoding !== 'buffer' && Buffer.isEncoding(options.encoding)) {
@@ -180,10 +180,13 @@ exports.execFile = function(file /*, args, options, callback*/) {
     var stderr = (typeof _stderr[0] === 'string') ?
       _stderr.join('') : Buffer.concat(_stderr, stderrLen);
 
-    if (encoding) {
-      stdout = stdout.toString(encoding);
-      stderr = stderr.toString(encoding);
-    }
+    stdoutEncoding = stdoutEncoding || encoding;
+    if (stdoutEncoding)
+      stdout = stdout.toString(stdoutEncoding);
+
+    stderrEncoding = stderrEncoding || encoding;
+    if (stderrEncoding)
+      stderr = stderr.toString(stderrEncoding);
 
     if (ex) {
       // Will be handled later
@@ -242,20 +245,22 @@ exports.execFile = function(file /*, args, options, callback*/) {
     }, options.timeout);
   }
 
-  // Use chunk.byteLength to get accurate count of bytes, but fall back to
-  // chunk.length in case someone does something like
-  // `child.stdout.setEncoding('utf8')` in userland. That means the bytes may
-  // be under-counted in that situation (if there are characters represented by
-  // more than one byte), but there doesn't seem to be a good fix that wouldn't
-  // be a semver-major (breaking) change.
-
   if (child.stdout) {
+    const stdoutState = child.stdout._readableState;
+
     child.stdout.addListener('data', function(chunk) {
-      stdoutLen += (chunk.byteLength || chunk.length);
+      // If `child.stdout.setEncoding('utf8') happened in userland, convert
+      // string to Buffer and save encoding for later.
+      if (stdoutState.decoder) {
+        stdoutEncoding = stdoutState.decoder.encoding;
+        chunk = Buffer.from(chunk, stdoutEncoding);
+      }
+
+      stdoutLen += chunk.byteLength;
 
       if (stdoutLen > options.maxBuffer) {
         ex = new Error('stdout maxBuffer exceeded');
-        stdoutLen -= (chunk.byteLength || chunk.length);
+        stdoutLen -= chunk.byteLength;
         kill();
       } else {
         _stdout.push(chunk);
@@ -264,12 +269,21 @@ exports.execFile = function(file /*, args, options, callback*/) {
   }
 
   if (child.stderr) {
+    const stderrState = child.stderr._readableState;
+
     child.stderr.addListener('data', function(chunk) {
-      stderrLen += (chunk.byteLength || chunk.length);
+      // If `child.stderr.setEncoding('utf8') happened in userland, convert
+      // string to Buffer and save encoding for later.
+      if (stderrState.decoder) {
+        stderrEncoding = stderrState.decoder.encoding;
+        chunk = Buffer.from(chunk, stderrEncoding);
+      }
+
+      stderrLen += chunk.byteLength;
 
       if (stderrLen > options.maxBuffer) {
         ex = new Error('stderr maxBuffer exceeded');
-        stderrLen -= (chunk.byteLength || chunk.length);
+        stderrLen -= chunk.byteLength;
         kill();
       } else {
         _stderr.push(chunk);

From 2d561580363e252f2b392765506133afa0443b31 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Fri, 20 May 2016 16:07:08 -0700
Subject: [PATCH 07/12] squash

---
 lib/child_process.js | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index c815416df12b0f..195b8e284f7401 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -145,7 +145,9 @@ exports.execFile = function(file /*, args, options, callback*/) {
     windowsVerbatimArguments: !!options.windowsVerbatimArguments
   });
 
-  var encoding, stdoutEncoding, stderrEncoding;
+  var encoding;
+  var stdoutState;
+  var stderrState;
   var _stdout = [];
   var _stderr = [];
   if (options.encoding !== 'buffer' && Buffer.isEncoding(options.encoding)) {
@@ -172,19 +174,23 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
     if (!callback) return;
 
-    // Merge chunks. _stdout/_stderr may contain strings if the calling code
-    // does something like `child.stdout.setEncoding('utf8')`
-    var stdout = (typeof _stdout[0] === 'string') ?
-      _stdout.join('') : Buffer.concat(_stdout, stdoutLen);
+    var stdout = Buffer.concat(_stdout, stdoutLen);
+    var stderr = Buffer.concat(_stderr, stderrLen);
 
-    var stderr = (typeof _stderr[0] === 'string') ?
-      _stderr.join('') : Buffer.concat(_stderr, stderrLen);
+    var stdoutEncoding = encoding;
+    var stderrEncoding = encoding;
+
+    if (stdoutState && stdoutState.decoder && stdoutState.decoder.encoding) {
+      stdoutEncoding = stdoutState.decoder.encoding;
+    }
+
+    if (stderrState && stderrState.decoder && stderrState.decoder.encoding) {
+      stderrEncoding = stderrState.decoder.encoding;
+    }
 
-    stdoutEncoding = stdoutEncoding || encoding;
     if (stdoutEncoding)
       stdout = stdout.toString(stdoutEncoding);
 
-    stderrEncoding = stderrEncoding || encoding;
     if (stderrEncoding)
       stderr = stderr.toString(stderrEncoding);
 
@@ -246,14 +252,13 @@ exports.execFile = function(file /*, args, options, callback*/) {
   }
 
   if (child.stdout) {
-    const stdoutState = child.stdout._readableState;
+    stdoutState = child.stdout._readableState;
 
     child.stdout.addListener('data', function(chunk) {
       // If `child.stdout.setEncoding('utf8') happened in userland, convert
       // string to Buffer and save encoding for later.
       if (stdoutState.decoder) {
-        stdoutEncoding = stdoutState.decoder.encoding;
-        chunk = Buffer.from(chunk, stdoutEncoding);
+        chunk = Buffer.from(chunk, stdoutState.decoder.encoding);
       }
 
       stdoutLen += chunk.byteLength;
@@ -269,14 +274,13 @@ exports.execFile = function(file /*, args, options, callback*/) {
   }
 
   if (child.stderr) {
-    const stderrState = child.stderr._readableState;
+    stderrState = child.stderr._readableState;
 
     child.stderr.addListener('data', function(chunk) {
       // If `child.stderr.setEncoding('utf8') happened in userland, convert
       // string to Buffer and save encoding for later.
       if (stderrState.decoder) {
-        stderrEncoding = stderrState.decoder.encoding;
-        chunk = Buffer.from(chunk, stderrEncoding);
+        chunk = Buffer.from(chunk, stderrState.decoder.encoding);
       }
 
       stderrLen += chunk.byteLength;

From bce02ef630381dadfb24ea66f4d8341a1a967eef Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Fri, 20 May 2016 20:06:03 -0700
Subject: [PATCH 08/12] squash

---
 lib/child_process.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 195b8e284f7401..7c2b8cdb4db0a8 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -180,11 +180,11 @@ exports.execFile = function(file /*, args, options, callback*/) {
     var stdoutEncoding = encoding;
     var stderrEncoding = encoding;
 
-    if (stdoutState && stdoutState.decoder && stdoutState.decoder.encoding) {
+    if (stdoutState.decoder) {
       stdoutEncoding = stdoutState.decoder.encoding;
     }
 
-    if (stderrState && stderrState.decoder && stderrState.decoder.encoding) {
+    if (stderrState.decoder) {
       stderrEncoding = stderrState.decoder.encoding;
     }
 

From a8ba1118f6c50a4011dfba4c6827760b51785b20 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Fri, 20 May 2016 23:17:45 -0700
Subject: [PATCH 09/12] squash: nothing but nits

---
 lib/child_process.js | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 7c2b8cdb4db0a8..ff09b491431f52 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -180,13 +180,11 @@ exports.execFile = function(file /*, args, options, callback*/) {
     var stdoutEncoding = encoding;
     var stderrEncoding = encoding;
 
-    if (stdoutState.decoder) {
+    if (stdoutState.decoder)
       stdoutEncoding = stdoutState.decoder.encoding;
-    }
 
-    if (stderrState.decoder) {
+    if (stderrState.decoder)
       stderrEncoding = stderrState.decoder.encoding;
-    }
 
     if (stdoutEncoding)
       stdout = stdout.toString(stdoutEncoding);
@@ -256,7 +254,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
     child.stdout.addListener('data', function(chunk) {
       // If `child.stdout.setEncoding('utf8') happened in userland, convert
-      // string to Buffer and save encoding for later.
+      // string to Buffer.
       if (stdoutState.decoder) {
         chunk = Buffer.from(chunk, stdoutState.decoder.encoding);
       }

From 32925da4a9799a17d9b08ebb38af4daebce9e07f Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Sat, 21 May 2016 14:05:18 -0700
Subject: [PATCH 10/12] squash

---
 lib/child_process.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index ff09b491431f52..efcdf867aa0035 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -180,10 +180,10 @@ exports.execFile = function(file /*, args, options, callback*/) {
     var stdoutEncoding = encoding;
     var stderrEncoding = encoding;
 
-    if (stdoutState.decoder)
+    if (stdoutState && stdoutState.decoder)
       stdoutEncoding = stdoutState.decoder.encoding;
 
-    if (stderrState.decoder)
+    if (stderrState && stderrState.decoder)
       stderrEncoding = stderrState.decoder.encoding;
 
     if (stdoutEncoding)
@@ -254,7 +254,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
 
     child.stdout.addListener('data', function(chunk) {
       // If `child.stdout.setEncoding('utf8') happened in userland, convert
-      // string to Buffer.
+      // string to Buffer`.
       if (stdoutState.decoder) {
         chunk = Buffer.from(chunk, stdoutState.decoder.encoding);
       }

From ec2cf57b3fcdc8df3127bf9b69f1ae4074e530b5 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Sat, 21 May 2016 17:03:46 -0700
Subject: [PATCH 11/12] squash: comment nit fixes

---
 lib/child_process.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index efcdf867aa0035..62b81d218fc4cf 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -253,8 +253,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
     stdoutState = child.stdout._readableState;
 
     child.stdout.addListener('data', function(chunk) {
-      // If `child.stdout.setEncoding('utf8') happened in userland, convert
-      // string to Buffer`.
+      // If `child.stdout.setEncoding('utf8')` happened in userland, convert
+      // string to Buffer.
       if (stdoutState.decoder) {
         chunk = Buffer.from(chunk, stdoutState.decoder.encoding);
       }
@@ -275,8 +275,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
     stderrState = child.stderr._readableState;
 
     child.stderr.addListener('data', function(chunk) {
-      // If `child.stderr.setEncoding('utf8') happened in userland, convert
-      // string to Buffer and save encoding for later.
+      // If `child.stderr.setEncoding('utf8')` happened in userland, convert
+      // string to Buffer.
       if (stderrState.decoder) {
         chunk = Buffer.from(chunk, stderrState.decoder.encoding);
       }

From 561c7983f31c1251e40c72690e7dff1d546e7211 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Tue, 24 May 2016 09:11:18 -0700
Subject: [PATCH 12/12] squash: fix comment

---
 lib/child_process.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 62b81d218fc4cf..085f50abe64a71 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -253,8 +253,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
     stdoutState = child.stdout._readableState;
 
     child.stdout.addListener('data', function(chunk) {
-      // If `child.stdout.setEncoding('utf8')` happened in userland, convert
-      // string to Buffer.
+      // If `child.stdout.setEncoding()` happened in userland, convert string to
+      // Buffer.
       if (stdoutState.decoder) {
         chunk = Buffer.from(chunk, stdoutState.decoder.encoding);
       }
@@ -275,8 +275,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
     stderrState = child.stderr._readableState;
 
     child.stderr.addListener('data', function(chunk) {
-      // If `child.stderr.setEncoding('utf8')` happened in userland, convert
-      // string to Buffer.
+      // If `child.stderr.setEncoding()` happened in userland, convert string to
+      // Buffer.
       if (stderrState.decoder) {
         chunk = Buffer.from(chunk, stderrState.decoder.encoding);
       }