2 files changed, 13 insertions, 9 deletions
diff --git a/lib/system/jssys.nim b/lib/system/jssys.nim
index 15b00f8f1..3b55f62ca 100644
--- a/lib/system/jssys.nim
+++ b/lib/system/jssys.nim
@@ -322,10 +322,10 @@ when defined(kwin):
       }
       print(buf);
     """
-    
+
 elif defined(nodejs):
   proc ewriteln(x: cstring) = log(x)
-  
+
   proc rawEcho {.compilerproc, asmNoStackFrame.} =
     asm """
       var buf = "";
@@ -339,12 +339,12 @@ else:
   var
     document {.importc, nodecl.}: ref TDocument
 
-  proc ewriteln(x: cstring) = 
+  proc ewriteln(x: cstring) =
     var node = document.getElementsByTagName("body")[0]
-    if node != nil: 
+    if node != nil:
       node.appendChild(document.createTextNode(x))
       node.appendChild(document.createElement("br"))
-    else: 
+    else:
       raise newException(ValueError, "<body> element does not exist yet!")
 
   proc rawEcho {.compilerproc.} =
@@ -563,7 +563,11 @@ proc nimCopy(x: pointer, ti: PNimType): pointer =
       }
     """
   of tyString:
-    asm "`result` = `x`.slice(0);"
+    asm """
+      if (`x` !== null) {
+        `result` = `x`.slice(0);
+      }
+    """
   else:
     result = x
 
@@ -679,7 +683,7 @@ proc nimParseBiggestFloat(s: string, number: var BiggestFloat, start = 0): int {
   if s[i] == 'I' or s[i] == 'i':
     if s[i+1] == 'N' or s[i+1] == 'n':
       if s[i+2] == 'F' or s[i+2] == 'f':
-        if s[i+3] notin IdentChars: 
+        if s[i+3] notin IdentChars:
           number = Inf*sign
           return i+3 - start
     return 0
diff --git a/lib/system/threads.nim b/lib/system/threads.nim
index 81d9e5d73..d8e011ecb 100644
--- a/lib/system/threads.nim
+++ b/lib/system/threads.nim
@@ -127,7 +127,7 @@ else:
     importc, header: "<pthread.h>".}
 
   proc pthread_create(a1: var TSysThread, a2: var TPthread_attr,
-            a3: proc (x: pointer) {.noconv.}, 
+            a3: proc (x: pointer): pointer {.noconv.}, 
             a4: pointer): cint {.importc: "pthread_create", 
             header: "<pthread.h>".}
   proc pthread_join(a1: TSysThread, a2: ptr pointer): cint {.
@@ -315,7 +315,7 @@ when defined(windows):
     threadProcWrapperBody(closure)
     # implicitly return 0
 else:
-  proc threadProcWrapper[TArg](closure: pointer) {.noconv.} = 
+  proc threadProcWrapper[TArg](closure: pointer): pointer {.noconv.} = 
     threadProcWrapperBody(closure)
 {.pop.}