1 files changed, 18 insertions, 12 deletions
diff --git a/lib/system/sysio.nim b/lib/system/sysio.nim
index 285bf1adc..40bbf97dc 100644
--- a/lib/system/sysio.nim
+++ b/lib/system/sysio.nim
@@ -143,19 +143,17 @@ proc getFileHandle*(f: File): FileHandle = c_fileno(f)
 
 proc readLine(f: File, line: var TaintedString): bool =
   var pos = 0
-  var sp: cint = 80
+
   # Use the currently reserved space for a first try
-  if line.string.isNil:
-    line = TaintedString(newStringOfCap(80))
-  else:
-    when not defined(nimscript):
-      sp = cint(cast[PGenericSeq](line.string).space)
+  var sp = line.string.len
+  if sp == 0:
+    sp = 80
     line.string.setLen(sp)
   while true:
     # memset to \L so that we can tell how far fgets wrote, even on EOF, where
     # fgets doesn't append an \L
-    c_memset(addr line.string[pos], '\L'.ord, sp)
-    var fgetsSuccess = c_fgets(addr line.string[pos], sp, f) != nil
+    nimSetMem(addr line.string[pos], '\L'.ord, sp)
+    var fgetsSuccess = c_fgets(addr line.string[pos], sp.cint, f) != nil
     if not fgetsSuccess: checkErr(f)
     let m = c_memchr(addr line.string[pos], '\L'.ord, sp)
     if m != nil:
@@ -200,9 +198,9 @@ proc write(f: File, b: bool) =
   if b: write(f, "true")
   else: write(f, "false")
 proc write(f: File, r: float32) =
-  if c_fprintf(f, "%g", r) < 0: checkErr(f)
+  if c_fprintf(f, "%.16g", r) < 0: checkErr(f)
 proc write(f: File, r: BiggestFloat) =
-  if c_fprintf(f, "%g", r) < 0: checkErr(f)
+  if c_fprintf(f, "%.16g", r) < 0: checkErr(f)
 
 proc write(f: File, c: char) = discard c_putc(cint(c), f)
 proc write(f: File, a: varargs[string, `$`]) =
@@ -417,18 +415,26 @@ proc setStdIoUnbuffered() =
     discard c_setvbuf(stdin, nil, IONBF, 0)
 
 when declared(stdout):
+  when defined(windows) and compileOption("threads"):
+    var echoLock: SysLock
+    initSysLock echoLock
+
   proc echoBinSafe(args: openArray[string]) {.compilerProc.} =
     # flockfile deadlocks some versions of Android 5.x.x
-    when not defined(windows) and not defined(android):
+    when not defined(windows) and not defined(android) and not defined(nintendoswitch):
       proc flockfile(f: File) {.importc, noDecl.}
       proc funlockfile(f: File) {.importc, noDecl.}
       flockfile(stdout)
+    when defined(windows) and compileOption("threads"):
+      acquireSys echoLock
     for s in args:
       discard c_fwrite(s.cstring, s.len, 1, stdout)
     const linefeed = "\n" # can be 1 or more chars
     discard c_fwrite(linefeed.cstring, linefeed.len, 1, stdout)
     discard c_fflush(stdout)
-    when not defined(windows) and not defined(android):
+    when not defined(windows) and not defined(android) and not defined(nintendoswitch):
       funlockfile(stdout)
+    when defined(windows) and compileOption("threads"):
+      releaseSys echoLock
 
 {.pop.}