3 files changed, 15 insertions, 9 deletions
diff --git a/lib/pure/strutils.nim b/lib/pure/strutils.nim
index de555917c..382eece7b 100755
--- a/lib/pure/strutils.nim
+++ b/lib/pure/strutils.nim
@@ -103,7 +103,7 @@ proc cmpIgnoreCase*(a, b: string): int {.noSideEffect,
   ## | 0 iff a == b
   ## | < 0 iff a < b
   ## | > 0 iff a > b
-  var i = 0
+  var i = 0
   var m = min(a.len, b.len)
   while i < m:
     result = ord(toLower(a[i])) - ord(toLower(b[i]))
@@ -406,7 +406,7 @@ proc ParseInt*(s: string): int {.noSideEffect, procvar,
   ## Parses a decimal integer value contained in `s`. If `s` is not
   ## a valid integer, `EInvalidValue` is raised.
   var L = parseutils.parseInt(s, result, 0)
-  if L != s.len or L == 0:
+  if L != s.len or L == 0:
     raise newException(EInvalidValue, "invalid integer: " & s)
 
 proc ParseBiggestInt*(s: string): biggestInt {.noSideEffect, procvar,
@@ -414,7 +414,7 @@ proc ParseBiggestInt*(s: string): biggestInt {.noSideEffect, procvar,
   ## Parses a decimal integer value contained in `s`. If `s` is not
   ## a valid integer, `EInvalidValue` is raised.
   var L = parseutils.parseBiggestInt(s, result, 0)
-  if L != s.len or L == 0:
+  if L != s.len or L == 0:
     raise newException(EInvalidValue, "invalid integer: " & s)
 
 proc ParseFloat*(s: string): float {.noSideEffect, procvar,
@@ -423,7 +423,7 @@ proc ParseFloat*(s: string): float {.noSideEffect, procvar,
   ## a valid floating point number, `EInvalidValue` is raised. ``NAN``,
   ## ``INF``, ``-INF`` are also supported (case insensitive comparison).
   var L = parseutils.parseFloat(s, result, 0)
-  if L != s.len or L == 0:
+  if L != s.len or L == 0:
     raise newException(EInvalidValue, "invalid float: " & s)
 
 proc ParseHexInt*(s: string): int {.noSideEffect, procvar,
@@ -952,7 +952,7 @@ type
   TFloatFormat* = enum
     ffDefault,    ## use the shorter floating point notation
     ffDecimal,    ## use decimal floating point notation
-    ffScientific  ## use scientific notation (using ``e``) character
+    ffScientific  ## use scientific notation (using ``e`` character)
 
 proc formatBiggestFloat*(f: BiggestFloat, format: TFloatFormat = ffDefault,
                          precision = 16): string {.noSideEffect,
@@ -1006,6 +1006,6 @@ when isMainModule:
                    it goes""", 10, false)
   assert formatBiggestFloat(0.00000000001, ffDecimal, 11) == "0.00000000001"
   assert formatBiggestFloat(0.00000000001, ffScientific, 1) == "1.0e-11"
-  
+  
   assert "$# $3 $# $#" % ["a", "b", "c"] == "a c b c"
 
diff --git a/lib/system.nim b/lib/system.nim
index 8fc4493dd..6490ce416 100755
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -650,13 +650,15 @@ proc setLen*[T](s: var seq[T], newlen: int) {.
   ## sets the length of `s` to `newlen`.
   ## ``T`` may be any sequence type.
   ## If the current length is greater than the new length,
-  ## ``s`` will be truncated.
+  ## ``s`` will be truncated. `s` cannot be nil! To initialize a sequence with
+  ## a size, use ``newSeq`` instead. 
 
 proc setLen*(s: var string, newlen: int) {.
   magic: "SetLengthStr", noSideEffect.}
   ## sets the length of `s` to `newlen`.
   ## If the current length is greater than the new length,
-  ## ``s`` will be truncated.
+  ## ``s`` will be truncated. `s` cannot be nil! To initialize a string with
+  ## a size, use ``newString`` instead. 
 
 proc newString*(len: int): string {.
   magic: "NewString", importc: "mnewString", noSideEffect.}
diff --git a/lib/system/gc.nim b/lib/system/gc.nim
index eb4811bf5..950b60c27 100755
--- a/lib/system/gc.nim
+++ b/lib/system/gc.nim
@@ -642,7 +642,11 @@ proc unmarkStackAndRegisters(gch: var TGcHeap) =
   var d = gch.decStack.d
   for i in 0..gch.decStack.len-1:
     assert isAllocatedPtr(allocator, d[i])
-    decRef(d[i]) # OPT: cannot create a cycle!
+    # decRef(d[i]) inlined: cannot create a cycle
+    var c = d[i]
+    if atomicDec(c.refcount, rcIncrement) <% rcIncrement:
+      rtlAddZCT(c)
+    assert c.typ != nil
   gch.decStack.len = 0
 
 proc collectCT(gch: var TGcHeap) =