fix #4417, update news

compiler/commands.nim

@@ -217,6 +217,15 @@ proc testCompileOptionArg*(switch, arg: string, info: TLineInfo): bool =
     of "none": result = gOptions * {optOptimizeSpeed, optOptimizeSize} == {}
     else: localError(info, errNoneSpeedOrSizeExpectedButXFound, arg)
   of "verbosity": result = $gVerbosity == arg
+  of "app":
+    case arg.normalize
+    of "gui":       result = contains(gGlobalOptions, optGenGuiApp)
+    of "console":   result = not contains(gGlobalOptions, optGenGuiApp)
+    of "lib":       result = contains(gGlobalOptions, optGenDynLib) and
+                      not contains(gGlobalOptions, optGenGuiApp)
+    of "staticlib": result = contains(gGlobalOptions, optGenStaticLib) and
+                      not contains(gGlobalOptions, optGenGuiApp)
+    else: localError(info, errGuiConsoleOrLibExpectedButXFound, arg)
   else: invalidCmdLineOption(passCmd1, switch, info)
 
 proc testCompileOption*(switch: string, info: TLineInfo): bool =

lib/system.nim

@@ -3670,3 +3670,8 @@ template closureScope*(body: untyped): untyped =
 
 when defined(nimconfig):
   include "system/nimscript"
+
+when defined(windows) and compileOption("app", "console"):
+  proc setConsoleOutputCP(codepage: cint): cint {.stdcall, dynlib: "kernel32",
+    importc: "SetConsoleOutputCP".}
+  discard setConsoleOutputCP(65001) # 65001 - utf-8 codepage

web/news/version_0_15_released.rst

@@ -26,7 +26,7 @@ Changes affecting backwards compatibility
 
     Warning: a [b] will be parsed as command syntax; spacing is deprecated
 
-  See `https://github.com/nim-lang/Nim/issues/3898`_ for the relevant
+  See `<https://github.com/nim-lang/Nim/issues/3898>`_ for the relevant
   discussion.
 - Overloading the special operators ``.``, ``.()``, ``.=``, ``()`` now
   should be enabled via ``{.experimental.}``.
@@ -52,6 +52,8 @@ that have tuple name:
   var rocketaims = initOrderedTable[string, Table[tuple[k: int8, v: int8], int64] ]()
   rocketaims["hi"] = {(k: -1.int8, v: 0.int8): 0.int64}.toTable()
 
+- Now when you compile console application for Windows, console output
+  encoding is automatically set to UTF-8.
 
 Library Additions
 -----------------