From 488ab8c01de69379406d937419fa3e5550e651c0 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Mon, 2 Aug 2021 16:25:12 -0700
Subject: [PATCH] chore: WriteEntry cleaner write() handling

---
 lib/write-entry.js  | 25 +++++++++++++++++--------
 test/write-entry.js | 14 ++++++++++++++
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/lib/write-entry.js b/lib/write-entry.js
index 4385c040..d9f4123f 100644
--- a/lib/write-entry.js
+++ b/lib/write-entry.js
@@ -150,7 +150,7 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
     })
 
     if (this.header.encode() && !this.noPax) {
-      this.write(new Pax({
+      super.write(new Pax({
         atime: this.portable ? null : this.header.atime,
         ctime: this.portable ? null : this.header.ctime,
         gid: this.portable ? null : this.header.gid,
@@ -165,7 +165,7 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
         nlink: this.portable ? null : this.stat.nlink,
       }).encode())
     }
-    this.write(this.header.block)
+    super.write(this.header.block)
   }
 
   [DIRECTORY] () {
@@ -286,10 +286,6 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
 
     const writeBuf = this.offset === 0 && bytesRead === this.buf.length ?
       this.buf : this.buf.slice(this.offset, this.offset + bytesRead)
-    this.remain -= writeBuf.length
-    this.blockRemain -= writeBuf.length
-    this.pos += writeBuf.length
-    this.offset += writeBuf.length
 
     const flushed = this.write(writeBuf)
     if (!flushed)
@@ -302,10 +298,23 @@ const WriteEntry = warner(class WriteEntry extends MiniPass {
     this.once('drain', cb)
   }
 
+  write (writeBuf) {
+    if (this.blockRemain < writeBuf.length) {
+      const er = new Error('writing more data than expected')
+      er.path = this.absolute
+      return this.emit('error', er)
+    }
+    this.remain -= writeBuf.length
+    this.blockRemain -= writeBuf.length
+    this.pos += writeBuf.length
+    this.offset += writeBuf.length
+    return super.write(writeBuf)
+  }
+
   [ONDRAIN] () {
     if (!this.remain) {
       if (this.blockRemain)
-        this.write(Buffer.alloc(this.blockRemain))
+        super.write(Buffer.alloc(this.blockRemain))
       return this[CLOSE](er => er ? this.emit('error', er) : this.end())
     }
 
@@ -461,7 +470,7 @@ const WriteEntryTar = warner(class WriteEntryTar extends MiniPass {
 
   end () {
     if (this.blockRemain)
-      this.write(Buffer.alloc(this.blockRemain))
+      super.write(Buffer.alloc(this.blockRemain))
     return super.end()
   }
 })
diff --git a/test/write-entry.js b/test/write-entry.js
index 9e5e33cd..30df5ebf 100644
--- a/test/write-entry.js
+++ b/test/write-entry.js
@@ -927,6 +927,20 @@ t.test('portable dir entries, no mtime', t => {
   })
 })
 
+t.test('writing more data than is appropriate', t => {
+  const path = t.testdir({
+    file: 'hello',
+  })
+  const wss = new WriteEntry(`${path}/file`)
+  wss.on('error', er => {
+    t.match(er, {
+      message: 'writing more data than expected',
+    })
+    t.end()
+  })
+  wss.on('stat', () => wss.write(Buffer.from('some more stuff')))
+})
+
 t.test('write entry from read entry', t => {
   const data = makeTar([
     {