Merge branch 'devel' of https://github.com/nim-lang/Nim into devel

14 files changed, 277 insertions, 98 deletions

diff --git a/appveyor.yml b/appveyor.yml
index 97be60951..45529cf00 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,14 +1,11 @@
 version: '{build}'
 
 environment:
+  DLLS_URL: https://nim-lang.org/download/dlls.zip
+  DLLS_ARCHIVE: dlls.zip
   MINGW_DIR: mingw64
   MINGW_URL: https://nim-lang.org/download/mingw64-6.3.0.7z
   MINGW_ARCHIVE: mingw64-6.3.0.7z
-  OPENBLAS_URL: https://sourceforge.net/projects/openblas/files/v0.3.5/OpenBLAS%200.3.5%20version.zip/download
-  OPENBLAS_ARCHIVE: OpenBLAS-0.3.5.zip
-  SQLITE_URL: http://www.sqlite.org/2017/sqlite-dll-win64-x64-3160200.zip
-  SQLITE_ARCHIVE: sqlite-dll-win64-x64-3160200.zip
-  platform: x64
 
   matrix:
     - NIM_TEST_PACKAGES: false
@@ -16,8 +13,7 @@ environment:
 
 cache:
     - '%MINGW_ARCHIVE%'
-    - '%SQLITE_ARCHIVE%'
-    - '%OPENBLAS_ARCHIVE%'
+    - '%DLLS_ARCHIVE%'
 
 matrix:
   #allow_failures:
@@ -26,23 +22,14 @@ matrix:
 
 install:
   - ps: Install-Product node 8 # node 8 or later is required to test js async stuff
-  - MKDIR %CD%\DIST
-  - MKDIR %CD%\DIST\PCRE
-  - nuget install pcre -Verbosity quiet -Version 8.33.0.1 -OutputDirectory %CD%\DIST\PCRE
-  - IF not exist "%SQLITE_ARCHIVE%" appveyor DownloadFile "%SQLITE_URL%" -FileName "%SQLITE_ARCHIVE%"
-  - 7z x -y "%SQLITE_ARCHIVE%" -o"%CD%\DIST"> nul
+  - IF not exist "%DLLS_ARCHIVE%" appveyor DownloadFile "%DLLS_URL%" -FileName "%DLLS_ARCHIVE%"
+  - 7z x -y "%DLLS_ARCHIVE%" -o"%CD%\BIN"> nul
   - IF not exist "%MINGW_ARCHIVE%" appveyor DownloadFile "%MINGW_URL%" -FileName "%MINGW_ARCHIVE%"
   - 7z x -y "%MINGW_ARCHIVE%" -o"%CD%\DIST"> nul
-  - IF not exist "%OPENBLAS_ARCHIVE%" appveyor DownloadFile "%OPENBLAS_URL%" -FileName "%OPENBLAS_ARCHIVE%"
-  - 7z x -y "%OPENBLAS_ARCHIVE%" -o"%CD%\DIST"> nul
   - SET PATH=%CD%\DIST\%MINGW_DIR%\BIN;%CD%\BIN;%PATH%
-  - IF "%PLATFORM%" == "x64" ( copy C:\OpenSSL-Win64\libeay32.dll %CD%\BIN\libeay64.dll & copy C:\OpenSSL-Win64\libeay32.dll %CD%\BIN\libeay32.dll & copy C:\OpenSSL-Win64\libssl32.dll %CD%\BIN\libssl64.dll & copy C:\OpenSSL-Win64\libssl32.dll %CD%\BIN\libssl32.dll )
-    ELSE ( copy C:\OpenSSL-Win32\libeay32.dll %CD%\BIN\libeay32.dll & copy C:\OpenSSL-Win32\libssl32.dll %CD%\BIN\libssl32.dll )
-  - IF "%PLATFORM%" == "x64" ( copy %CD%\DIST\sqlite3.dll %CD%\BIN\sqlite3_64.dll ) ELSE ( copy %CD%\DIST\sqlite3.dll %CD%\BIN\sqlite3_32.dll )
-  - IF "%PLATFORM%" == "x64" ( copy %CD%\DIST\PCRE\pcre.redist.8.33.0.1\build\native\bin\v100\x64\Release\dynamic\utf8\pcre8.dll %CD%\bin\pcre64.dll ) ELSE ( copy %CD%\DIST\PCRE\pcre.redist.8.33.0.1\build\native\bin\v100\Win32\Release\dynamic\utf8\pcre8.dll %CD%\bin\pcre32.dll )
   - git clone --depth 1 https://github.com/nim-lang/csources
   - cd csources
-  - IF "%PLATFORM%" == "x64" ( build64.bat ) else ( build.bat )
+  - build64.bat
   - cd ..
 
 build_script:
diff --git a/compiler/layouter.nim b/compiler/layouter.nim
index 3ac907f1d..057bad5ba 100644
--- a/compiler/layouter.nim
+++ b/compiler/layouter.nim
@@ -346,7 +346,7 @@ proc emitTok*(em: var Emitter; L: TLexer; tok: TToken) =
     if endsInAlpha(em):
       wrSpace em
     elif not em.inquote and not endsInWhite(em) and
-        em.lastTok notin openPars and not em.lastTokWasTerse:
+        em.lastTok notin (openPars+{tkOpr, tkDotDot}) and not em.lastTokWasTerse:
       #and tok.tokType in oprSet
       wrSpace em
 
@@ -392,8 +392,8 @@ proc emitTok*(em: var Emitter; L: TLexer; tok: TToken) =
     wr(em, TokTypeToStr[tok.tokType], ltOther)
     if not em.inquote: wrSpace(em)
   of tkOpr, tkDotDot:
-    if ((tok.strongSpaceA == 0 and tok.strongSpaceB == 0) or em.inquote) and
-      tok.ident.s notin ["<", ">", "<=", ">=", "==", "!="]:
+    if em.inquote or ((tok.strongSpaceA == 0 and tok.strongSpaceB == 0) and
+        tok.ident.s notin ["<", ">", "<=", ">=", "==", "!="]):
       # bug #9504: remember to not spacify a keyword:
       lastTokWasTerse = true
       # if not surrounded by whitespace, don't produce any whitespace either:
diff --git a/compiler/lexer.nim b/compiler/lexer.nim
index 421a83c19..97fa91b3a 100644
--- a/compiler/lexer.nim
+++ b/compiler/lexer.nim
@@ -173,7 +173,7 @@ proc isNimIdentifier*(s: string): bool =
       inc(i)
     result = true
 
-proc tokToStr*(tok: TToken): string =
+proc `$`*(tok: TToken): string =
   case tok.tokType
   of tkIntLit..tkInt64Lit: result = $tok.iNumber
   of tkFloatLit..tkFloat64Lit: result = $tok.fNumber
@@ -188,11 +188,11 @@ proc tokToStr*(tok: TToken): string =
 
 proc prettyTok*(tok: TToken): string =
   if isKeyword(tok.tokType): result = "keyword " & tok.ident.s
-  else: result = tokToStr(tok)
+  else: result = $tok
 
 proc printTok*(conf: ConfigRef; tok: TToken) =
   msgWriteln(conf, $tok.line & ":" & $tok.col & "\t" &
-      TokTypeToStr[tok.tokType] & " " & tokToStr(tok))
+      TokTypeToStr[tok.tokType] & " " & $tok)
 
 proc initToken*(L: var TToken) =
   L.tokType = tkInvalid
diff --git a/compiler/nimconf.nim b/compiler/nimconf.nim
index 02d1e7d2a..f518b3abf 100644
--- a/compiler/nimconf.nim
+++ b/compiler/nimconf.nim
@@ -123,31 +123,31 @@ proc parseDirective(L: var TLexer, tok: var TToken; config: ConfigRef; condStack
   of wEnd: doEnd(L, tok, condStack)
   of wWrite:
     ppGetTok(L, tok)
-    msgs.msgWriteln(config, strtabs.`%`(tokToStr(tok), config.configVars,
+    msgs.msgWriteln(config, strtabs.`%`($tok, config.configVars,
                                 {useEnvironment, useKey}))
     ppGetTok(L, tok)
   else:
     case tok.ident.s.normalize
     of "putenv":
       ppGetTok(L, tok)
-      var key = tokToStr(tok)
+      var key = $tok
       ppGetTok(L, tok)
-      os.putEnv(key, tokToStr(tok))
+      os.putEnv(key, $tok)
       ppGetTok(L, tok)
     of "prependenv":
       ppGetTok(L, tok)
-      var key = tokToStr(tok)
+      var key = $tok
       ppGetTok(L, tok)
-      os.putEnv(key, tokToStr(tok) & os.getEnv(key))
+      os.putEnv(key, $tok & os.getEnv(key))
       ppGetTok(L, tok)
     of "appendenv":
       ppGetTok(L, tok)
-      var key = tokToStr(tok)
+      var key = $tok
       ppGetTok(L, tok)
-      os.putEnv(key, os.getEnv(key) & tokToStr(tok))
+      os.putEnv(key, os.getEnv(key) & $tok)
       ppGetTok(L, tok)
     else:
-      lexMessage(L, errGenerated, "invalid directive: '$1'" % tokToStr(tok))
+      lexMessage(L, errGenerated, "invalid directive: '$1'" % $tok)
 
 proc confTok(L: var TLexer, tok: var TToken; config: ConfigRef; condStack: var seq[bool]) =
   ppGetTok(L, tok)
@@ -156,7 +156,7 @@ proc confTok(L: var TLexer, tok: var TToken; config: ConfigRef; condStack: var s
 
 proc checkSymbol(L: TLexer, tok: TToken) =
   if tok.tokType notin {tkSymbol..tkInt64Lit, tkStrLit..tkTripleStrLit}:
-    lexMessage(L, errGenerated, "expected identifier, but got: " & tokToStr(tok))
+    lexMessage(L, errGenerated, "expected identifier, but got: " & $tok)
 
 proc parseAssignment(L: var TLexer, tok: var TToken;
                      config: ConfigRef; condStack: var seq[bool]) =
@@ -164,21 +164,21 @@ proc parseAssignment(L: var TLexer, tok: var TToken;
     confTok(L, tok, config, condStack)           # skip unnecessary prefix
   var info = getLineInfo(L, tok) # save for later in case of an error
   checkSymbol(L, tok)
-  var s = tokToStr(tok)
+  var s = $tok
   confTok(L, tok, config, condStack)             # skip symbol
   var val = ""
   while tok.tokType == tkDot:
     add(s, '.')
     confTok(L, tok, config, condStack)
     checkSymbol(L, tok)
-    add(s, tokToStr(tok))
+    add(s, $tok)
     confTok(L, tok, config, condStack)
   if tok.tokType == tkBracketLe:
     # BUGFIX: val, not s!
     confTok(L, tok, config, condStack)
     checkSymbol(L, tok)
     add(val, '[')
-    add(val, tokToStr(tok))
+    add(val, $tok)
     confTok(L, tok, config, condStack)
     if tok.tokType == tkBracketRi: confTok(L, tok, config, condStack)
     else: lexMessage(L, errGenerated, "expected closing ']'")
@@ -188,12 +188,12 @@ proc parseAssignment(L: var TLexer, tok: var TToken;
     if len(val) > 0: add(val, ':')
     confTok(L, tok, config, condStack)           # skip ':' or '=' or '%'
     checkSymbol(L, tok)
-    add(val, tokToStr(tok))
+    add(val, $tok)
     confTok(L, tok, config, condStack)           # skip symbol
     while tok.ident != nil and tok.ident.s == "&":
       confTok(L, tok, config, condStack)
       checkSymbol(L, tok)
-      add(val, tokToStr(tok))
+      add(val, $tok)
       confTok(L, tok, config, condStack)
   if percent:
     processSwitch(s, strtabs.`%`(val, config.configVars,
diff --git a/compiler/parser.nim b/compiler/parser.nim
index eda75f926..65fb2c5a3 100644
--- a/compiler/parser.nim
+++ b/compiler/parser.nim
@@ -343,13 +343,13 @@ proc parseSymbol(p: var TParser, mode = smNormal): PNode =
         var accm = ""
         while p.tok.tokType in {tkOpr, tkDot, tkDotDot, tkEquals,
                                 tkParLe..tkParDotRi}:
-          accm.add(tokToStr(p.tok))
+          accm.add($p.tok)
           getTok(p)
         let node = newNodeI(nkIdent, lineinfo)
         node.ident = p.lex.cache.getIdent(accm)
         result.add(node)
       of tokKeywordLow..tokKeywordHigh, tkSymbol, tkIntLit..tkCharLit:
-        result.add(newIdentNodeP(p.lex.cache.getIdent(tokToStr(p.tok)), p))
+        result.add(newIdentNodeP(p.lex.cache.getIdent($p.tok), p))
         getTok(p)
       else:
         parMessage(p, errIdentifierExpected, p.tok)
@@ -903,6 +903,8 @@ proc parsePragma(p: var TParser): PNode =
   #| pragma = '{.' optInd (exprColonExpr comma?)* optPar ('.}' | '}')
   result = newNodeP(nkPragma, p)
   inc p.inPragma
+  when defined(nimpretty):
+    inc p.em.keepIndents
   getTok(p)
   optInd(p, result)
   while p.tok.tokType notin {tkCurlyDotRi, tkCurlyRi, tkEof}:
@@ -921,6 +923,8 @@ proc parsePragma(p: var TParser): PNode =
   else:
     parMessage(p, "expected '.}'")
   dec p.inPragma
+  when defined(nimpretty):
+    dec p.em.keepIndents
 
 proc identVis(p: var TParser; allowDot=false): PNode =
   #| identVis = symbol opr?  # postfix position
diff --git a/doc/tut1.rst b/doc/tut1.rst
index 161b4b904..ff53d3f37 100644
--- a/doc/tut1.rst
+++ b/doc/tut1.rst
@@ -56,7 +56,7 @@ To compile a release version use::
   nim c -d:release greetings.nim
 
 By default the Nim compiler generates a large amount of runtime checks
-aiming for your debugging pleasure. With ``-d:release`` these checks are
+aiming for your debugging pleasure. With ``-d:release`` some checks are
 `turned off and optimizations are turned on
 <nimc.html#compiler-usage-compile-time-symbols>`_.
 
diff --git a/lib/pure/asyncdispatch.nim b/lib/pure/asyncdispatch.nim
index ea35a444d..382d9d44a 100644
--- a/lib/pure/asyncdispatch.nim
+++ b/lib/pure/asyncdispatch.nim
@@ -568,7 +568,7 @@ when defined(windows) or defined(nimdoc):
             if flags.isDisconnectionError(errcode):
               retFuture.complete()
             else:
-              retFuture.fail(newException(OSError, osErrorMsg(errcode)))
+              retFuture.fail(newOSError(errcode))
     )
 
     let ret = WSASend(socket.SocketHandle, addr dataBuf, 1, addr bytesReceived,
@@ -1134,11 +1134,6 @@ else:
     var data = newAsyncData()
     p.selector.registerHandle(fd.SocketHandle, {}, data)
 
-  proc closeSocket*(sock: AsyncFD) =
-    let disp = getGlobalDispatcher()
-    disp.selector.unregister(sock.SocketHandle)
-    sock.SocketHandle.close()
-
   proc unregister*(fd: AsyncFD) =
     getGlobalDispatcher().selector.unregister(fd.SocketHandle)
 
@@ -1174,7 +1169,9 @@ else:
     let p = getGlobalDispatcher()
     not p.selector.isEmpty() or p.timers.len != 0 or p.callbacks.len != 0
 
-  template processBasicCallbacks(ident, rwlist: untyped) =
+  proc processBasicCallbacks(
+    fd: AsyncFD, event: Event
+  ): tuple[readCbListCount, writeCbListCount: int] =
     # Process pending descriptor and AsyncEvent callbacks.
     #
     # Invoke every callback stored in `rwlist`, until one
@@ -1187,32 +1184,46 @@ else:
     # or it can be possible to fall into endless cycle.
     var curList: seq[Callback]
 
-    withData(p.selector, ident, adata) do:
-      shallowCopy(curList, adata.rwlist)
-      adata.rwlist = newSeqOfCap[Callback](InitCallbackListSize)
+    let selector = getGlobalDispatcher().selector
+    withData(selector, fd.int, fdData):
+      case event
+      of Event.Read:
+        shallowCopy(curList, fdData.readList)
+        fdData.readList = newSeqOfCap[Callback](InitCallbackListSize)
+      of Event.Write:
+        shallowCopy(curList, fdData.writeList)
+        fdData.writeList = newSeqOfCap[Callback](InitCallbackListSize)
+      else:
+        assert false, "Cannot process callbacks for " & $event
 
     let newLength = max(len(curList), InitCallbackListSize)
     var newList = newSeqOfCap[Callback](newLength)
 
     for cb in curList:
-      if len(newList) > 0:
-        # A callback has already returned with EAGAIN, don't call any others
-        # until next `poll`.
+      if not cb(fd):
+        # Callback wants to be called again.
         newList.add(cb)
+        # This callback has returned with EAGAIN, so we don't need to
+        # call any other callbacks as they are all waiting for the same event
+        # on the same fd.
+        break
+
+    withData(selector, fd.int, fdData) do:
+      # Descriptor is still present in the queue.
+      case event
+      of Event.Read:
+        fdData.readList = newList & fdData.readList
+      of Event.Write:
+        fdData.writeList = newList & fdData.writeList
       else:
-        if not cb(fd.AsyncFD):
-          # Callback wants to be called again.
-          newList.add(cb)
+        assert false, "Cannot process callbacks for " & $event
 
-    withData(p.selector, ident, adata) do:
-      # descriptor still present in queue.
-      adata.rwlist = newList & adata.rwlist
-      rLength = len(adata.readList)
-      wLength = len(adata.writeList)
+      result.readCbListCount = len(fdData.readList)
+      result.writeCbListCount = len(fdData.writeList)
     do:
-      # descriptor was unregistered in callback via `unregister()`.
-      rLength = -1
-      wLength = -1
+      # Descriptor was unregistered in callback via `unregister()`.
+      result.readCbListCount = -1
+      result.writeCbListCount = -1
 
   template processCustomCallbacks(ident: untyped) =
     # Process pending custom event callbacks. Custom events are
@@ -1221,7 +1232,7 @@ else:
     # so there is no need to iterate over list.
     var curList: seq[Callback]
 
-    withData(p.selector, ident, adata) do:
+    withData(p.selector, ident.int, adata) do:
       shallowCopy(curList, adata.readList)
       adata.readList = newSeqOfCap[Callback](InitCallbackListSize)
 
@@ -1232,16 +1243,33 @@ else:
     if not cb(fd.AsyncFD):
       newList.add(cb)
 
-    withData(p.selector, ident, adata) do:
+    withData(p.selector, ident.int, adata) do:
       # descriptor still present in queue.
       adata.readList = newList & adata.readList
       if len(adata.readList) == 0:
         # if no callbacks registered with descriptor, unregister it.
-        p.selector.unregister(fd)
+        p.selector.unregister(fd.int)
     do:
       # descriptor was unregistered in callback via `unregister()`.
       discard
 
+  proc closeSocket*(sock: AsyncFD) =
+    let selector = getGlobalDispatcher().selector
+    if sock.SocketHandle notin selector:
+      raise newException(ValueError, "File descriptor not registered.")
+
+    let data = selector.getData(sock.SocketHandle)
+    sock.unregister()
+    sock.SocketHandle.close()
+    # We need to unblock the read and write callbacks which could still be
+    # waiting for the socket to become readable and/or writeable.
+    for cb in data.readList & data.writeList:
+      if not cb(sock):
+        raise newException(
+          ValueError, "Expecting async operations to stop when fd has closed."
+        )
+
+
   proc runOnce(timeout = 500): bool =
     let p = getGlobalDispatcher()
     when ioselSupportedPlatform:
@@ -1257,41 +1285,42 @@ else:
     let nextTimer = processTimers(p, result)
     var count = p.selector.selectInto(adjustTimeout(timeout, nextTimer), keys)
     for i in 0..<count:
-      var custom = false
-      let fd = keys[i].fd
+      let fd = keys[i].fd.AsyncFD
       let events = keys[i].events
-      var rLength = 0 # len(data.readList) after callback
-      var wLength = 0 # len(data.writeList) after callback
+      var (readCbListCount, writeCbListCount) = (0, 0)
 
       if Event.Read in events or events == {Event.Error}:
-        processBasicCallbacks(fd, readList)
+        (readCbListCount, writeCbListCount) =
+          processBasicCallbacks(fd, Event.Read)
         result = true
 
       if Event.Write in events or events == {Event.Error}:
-        processBasicCallbacks(fd, writeList)
+        (readCbListCount, writeCbListCount) =
+          processBasicCallbacks(fd, Event.Write)
         result = true
 
+      var isCustomEvent = false
       if Event.User in events:
-        processBasicCallbacks(fd, readList)
-        custom = true
-        if rLength == 0:
-          p.selector.unregister(fd)
+        (readCbListCount, writeCbListCount) =
+          processBasicCallbacks(fd, Event.Read)
+        isCustomEvent = true
+        if readCbListCount == 0:
+          p.selector.unregister(fd.int)
         result = true
 
       when ioselSupportedPlatform:
         if (customSet * events) != {}:
-          custom = true
+          isCustomEvent = true
           processCustomCallbacks(fd)
           result = true
 
       # because state `data` can be modified in callback we need to update
       # descriptor events with currently registered callbacks.
-      if not custom:
+      if not isCustomEvent and (readCbListCount != -1 and writeCbListCount != -1):
         var newEvents: set[Event] = {}
-        if rLength != -1 and wLength != -1:
-          if rLength > 0: incl(newEvents, Event.Read)
-          if wLength > 0: incl(newEvents, Event.Write)
-          p.selector.updateHandle(SocketHandle(fd), newEvents)
+        if readCbListCount > 0: incl(newEvents, Event.Read)
+        if writeCbListCount > 0: incl(newEvents, Event.Write)
+        p.selector.updateHandle(SocketHandle(fd), newEvents)
 
     # Timer processing.
     discard processTimers(p, result)
@@ -1370,7 +1399,7 @@ else:
           if flags.isDisconnectionError(lastError):
             retFuture.complete()
           else:
-            retFuture.fail(newException(OSError, osErrorMsg(lastError)))
+            retFuture.fail(newOSError(lastError))
         else:
           result = false # We still want this callback to be called.
       else:
diff --git a/lib/pure/asyncfutures.nim b/lib/pure/asyncfutures.nim
index 9af72f8b3..e86a34d81 100644
--- a/lib/pure/asyncfutures.nim
+++ b/lib/pure/asyncfutures.nim
@@ -393,11 +393,13 @@ proc asyncCheck*[T](future: Future[T]) =
   ## This should be used instead of ``discard`` to discard void futures,
   ## or use ``waitFor`` if you need to wait for the future's completion.
   assert(not future.isNil, "Future is nil")
-  future.callback =
-    proc () =
-      if future.failed:
-        injectStacktrace(future)
-        raise future.error
+  # TODO: We can likely look at the stack trace here and inject the location
+  # where the `asyncCheck` was called to give a better error stack message.
+  proc asyncCheckCallback() =
+    if future.failed:
+      injectStacktrace(future)
+      raise future.error
+  future.callback = asyncCheckCallback
 
 proc `and`*[T, Y](fut1: Future[T], fut2: Future[Y]): Future[void] =
   ## Returns a future which will complete once both ``fut1`` and ``fut2``
diff --git a/lib/pure/includes/oserr.nim b/lib/pure/includes/oserr.nim
index 68ce5d95f..34d8d0085 100644
--- a/lib/pure/includes/oserr.nim
+++ b/lib/pure/includes/oserr.nim
@@ -57,8 +57,10 @@ proc osErrorMsg*(errorCode: OSErrorCode): string =
     if errorCode != OSErrorCode(0'i32):
       result = $c_strerror(errorCode.int32)
 
-proc raiseOSError*(errorCode: OSErrorCode; additionalInfo = "") {.noinline.} =
-  ## Raises an `OSError exception <system.html#OSError>`_.
+proc newOSError*(
+  errorCode: OSErrorCode, additionalInfo = ""
+): owned(ref OSError) {.noinline.} =
+  ## Creates a new `OSError exception <system.html#OSError>`_.
   ##
   ## The ``errorCode`` will determine the
   ## message, `osErrorMsg proc <#osErrorMsg,OSErrorCode>`_ will be used
@@ -82,7 +84,14 @@ proc raiseOSError*(errorCode: OSErrorCode; additionalInfo = "") {.noinline.} =
     e.msg.addQuoted additionalInfo
   if e.msg == "":
     e.msg = "unknown OS error"
-  raise e
+  return e
+
+proc raiseOSError*(errorCode: OSErrorCode, additionalInfo = "") {.noinline.} =
+  ## Raises an `OSError exception <system.html#OSError>`_.
+  ##
+  ## Read the description of the `newOSError proc <#newOSError,OSErrorCode,string>`_ to learn
+  ## how the exception object is created.
+  raise newOSError(errorCode, additionalInfo)
 
 {.push stackTrace:off.}
 proc osLastError*(): OSErrorCode {.sideEffect.} =
diff --git a/lib/system.nim b/lib/system.nim
index 65f04a4ca..bebc9e336 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -3776,8 +3776,11 @@ proc quit*(errormsg: string, errorcode = QuitFailure) {.noReturn.} =
   when defined(nimscript) or defined(js) or (hostOS == "standalone"):
     echo errormsg
   else:
-    cstderr.rawWrite(errormsg)
-    cstderr.rawWrite("\n")
+    when nimvm:
+      echo errormsg
+    else:
+      cstderr.rawWrite(errormsg)
+      cstderr.rawWrite("\n")
   quit(errorcode)
 
 {.pop.} # checks
diff --git a/nimpretty/tests/exhaustive.nim b/nimpretty/tests/exhaustive.nim
index 2f8fe03f2..8280420c5 100644
--- a/nimpretty/tests/exhaustive.nim
+++ b/nimpretty/tests/exhaustive.nim
@@ -409,3 +409,26 @@ type
     ccFastCall,               # fastcall (pass parameters in registers)
     ccClosure,        # proc has a closure
     ccNoConvention       # needed for generating proper C procs sometimes
+
+
+proc isValid1*[A](s: HashSet[A]): bool {.deprecated:
+    "Deprecated since v0.20; sets are initialized by default".} =
+  ## Returns `true` if the set has been initialized (with `initHashSet proc
+  ## <#initHashSet,int>`_ or `init proc <#init,HashSet[A],int>`_).
+  result = s.data.len > 0
+  # bug #11468
+
+assert $type(a) == "Option[system.int]"
+foo(a, $type(b), c)
+foo(type(b), c) # this is ok
+
+proc `<`*[A](s, t: A): bool = discard
+proc `==`*[A](s, t: HashSet[A]): bool = discard
+proc `<=`*[A](s, t: HashSet[A]): bool = discard
+
+# these are ok:
+proc `$`*[A](s: HashSet[A]): string = discard
+proc `*`*[A](s1, s2: HashSet[A]): HashSet[A] {.inline.} = discard
+proc `-+-`*[A](s1, s2: HashSet[A]): HashSet[A] {.inline.} = discard
+
+# bug #11470
diff --git a/nimpretty/tests/expected/exhaustive.nim b/nimpretty/tests/expected/exhaustive.nim
index 75580081d..4e90faa25 100644
--- a/nimpretty/tests/expected/exhaustive.nim
+++ b/nimpretty/tests/expected/exhaustive.nim
@@ -419,3 +419,26 @@ type
     ccFastCall,    # fastcall (pass parameters in registers)
     ccClosure,     # proc has a closure
     ccNoConvention # needed for generating proper C procs sometimes
+
+
+proc isValid1*[A](s: HashSet[A]): bool {.deprecated:
+    "Deprecated since v0.20; sets are initialized by default".} =
+  ## Returns `true` if the set has been initialized (with `initHashSet proc
+  ## <#initHashSet,int>`_ or `init proc <#init,HashSet[A],int>`_).
+  result = s.data.len > 0
+  # bug #11468
+
+assert $type(a) == "Option[system.int]"
+foo(a, $type(b), c)
+foo(type(b), c) # this is ok
+
+proc `<`*[A](s, t: A): bool = discard
+proc `==`*[A](s, t: HashSet[A]): bool = discard
+proc `<=`*[A](s, t: HashSet[A]): bool = discard
+
+# these are ok:
+proc `$`*[A](s: HashSet[A]): string = discard
+proc `*`*[A](s1, s2: HashSet[A]): HashSet[A] {.inline.} = discard
+proc `-+-`*[A](s1, s2: HashSet[A]): HashSet[A] {.inline.} = discard
+
+# bug #11470
diff --git a/nimsuggest/nimsuggest.nim b/nimsuggest/nimsuggest.nim
index 97dd487aa..98e2d89c3 100644
--- a/nimsuggest/nimsuggest.nim
+++ b/nimsuggest/nimsuggest.nim
@@ -224,8 +224,8 @@ proc executeEpc(cmd: IdeCmd, args: SexpNode;
   execute(cmd, file, dirtyfile, int(line), int(column), graph)
 
 proc returnEpc(socket: Socket, uid: BiggestInt, s: SexpNode|string,
-               return_symbol = "return") =
-  let response = $convertSexp([newSSymbol(return_symbol), uid, s])
+               returnSymbol = "return") =
+  let response = $convertSexp([newSSymbol(returnSymbol), uid, s])
   socket.send(toHex(len(response), 6))
   socket.send(response)
 
diff --git a/tests/async/tasyncclosestall.nim b/tests/async/tasyncclosestall.nim
new file mode 100644
index 000000000..e10e23074
--- /dev/null
+++ b/tests/async/tasyncclosestall.nim
@@ -0,0 +1,99 @@
+discard """
+  outputsub: "send has errored. As expected. All good!"
+  exitcode: 0
+"""
+import asyncdispatch, asyncnet
+
+when defined(windows):
+  from winlean import ERROR_NETNAME_DELETED
+else:
+  from posix import EBADF
+
+# This reproduces a case where a socket remains stuck waiting for writes
+# even when the socket is closed.
+const
+  port = Port(50726)
+  timeout = 5000
+
+var sent = 0
+
+proc keepSendingTo(c: AsyncSocket) {.async.} =
+  while true:
+    # This write will eventually get stuck because the client is not reading
+    # its messages.
+    let sendFut = c.send("Foobar" & $sent & "\n", flags = {})
+    if not await withTimeout(sendFut, timeout):
+      # The write is stuck. Let's simulate a scenario where the socket
+      # does not respond to PING messages, and we close it. The above future
+      # should complete after the socket is closed, not continue stalling.
+      echo("Socket has stalled, closing it")
+      c.close()
+
+      let timeoutFut = withTimeout(sendFut, timeout)
+      yield timeoutFut
+      if timeoutFut.failed:
+        let errCode = ((ref OSError)(timeoutFut.error)).errorCode
+        # The behaviour differs across platforms. On Windows ERROR_NETNAME_DELETED
+        # is raised which we classif as a "diconnection error", hence we overwrite
+        # the flags above in the `send` call so that this error is raised.
+        #
+        # On Linux the EBADF error code is raised, this is because the socket
+        # is closed.
+        #
+        # This means that by default the behaviours will differ between Windows
+        # and Linux. I think this is fine though, it makes sense mainly because
+        # Windows doesn't use a IO readiness model. We can fix this later if
+        # necessary to reclassify ERROR_NETNAME_DELETED as not a "disconnection
+        # error" (TODO)
+        when defined(windows):
+          if errCode == ERROR_NETNAME_DELETED:
+            echo("send has errored. As expected. All good!")
+            quit(QuitSuccess)
+          else:
+            raise newException(ValueError, "Test failed. Send failed with code " & $errCode)
+        else:
+          if errCode == EBADF:
+            echo("send has errored. As expected. All good!")
+            quit(QuitSuccess)
+          else:
+            raise newException(ValueError, "Test failed. Send failed with code " & $errCode)
+
+      # The write shouldn't succeed and also shouldn't be stalled.
+      if timeoutFut.read():
+        raise newException(ValueError, "Test failed. Send was expected to fail.")
+      else:
+        raise newException(ValueError, "Test failed. Send future is still stalled.")
+    sent.inc(1)
+
+proc startClient() {.async.} =
+  let client = newAsyncSocket()
+  await client.connect("localhost", port)
+  echo("Connected")
+
+  let firstLine = await client.recvLine()
+  echo("Received first line as a client: ", firstLine)
+  echo("Now not reading anymore")
+  while true: await sleepAsync(1000)
+
+proc debug() {.async.} =
+  while true:
+    echo("Sent ", sent)
+    await sleepAsync(1000)
+
+proc server() {.async.} =
+  var s = newAsyncSocket()
+  s.setSockOpt(OptReuseAddr, true)
+  s.bindAddr(port)
+  s.listen()
+
+  # We're now ready to accept connections, so start the client
+  asyncCheck startClient()
+  asyncCheck debug()
+
+  while true:
+    let client = await accept(s)
+    asyncCheck keepSendingTo(client)
+
+when isMainModule:
+  waitFor server()
+