1 files changed, 14 insertions, 13 deletions
diff --git a/compiler/guards.nim b/compiler/guards.nim
index cedd2be2b..bc802ae33 100644
--- a/compiler/guards.nim
+++ b/compiler/guards.nim
@@ -13,29 +13,30 @@ import ast, astalgo, msgs, magicsys, nimsets, trees, types, renderer, idents,
   saturate
 
 const
-  someEq = {mEqI, mEqI64, mEqF64, mEqEnum, mEqCh, mEqB, mEqRef, mEqProc,
+  someEq = {mEqI, mEqF64, mEqEnum, mEqCh, mEqB, mEqRef, mEqProc,
     mEqUntracedRef, mEqStr, mEqSet, mEqCString}
 
   # set excluded here as the semantics are vastly different:
-  someLe = {mLeI, mLeI64, mLeF64, mLeU, mLeU64, mLeEnum,
+  someLe = {mLeI, mLeF64, mLeU, mLeU64, mLeEnum,
             mLeCh, mLeB, mLePtr, mLeStr}
-  someLt = {mLtI, mLtI64, mLtF64, mLtU, mLtU64, mLtEnum,
+  someLt = {mLtI, mLtF64, mLtU, mLtU64, mLtEnum,
             mLtCh, mLtB, mLtPtr, mLtStr}
 
-  someLen = {mLengthOpenArray, mLengthStr, mLengthArray, mLengthSeq}
+  someLen = {mLengthOpenArray, mLengthStr, mLengthArray, mLengthSeq,
+             mXLenStr, mXLenSeq}
 
   someIn = {mInRange, mInSet}
 
   someHigh = {mHigh}
   # we don't list unsigned here because wrap around semantics suck for
   # proving anything:
-  someAdd = {mAddI, mAddI64, mAddF64, mSucc}
-  someSub = {mSubI, mSubI64, mSubF64, mPred}
-  someMul = {mMulI, mMulI64, mMulF64}
-  someDiv = {mDivI, mDivI64, mDivF64}
-  someMod = {mModI, mModI64}
-  someMax = {mMaxI, mMaxI64, mMaxF64}
-  someMin = {mMinI, mMinI64, mMinF64}
+  someAdd = {mAddI, mAddF64, mSucc}
+  someSub = {mSubI, mSubF64, mPred}
+  someMul = {mMulI, mMulF64}
+  someDiv = {mDivI, mDivF64}
+  someMod = {mModI}
+  someMax = {mMaxI, mMaxF64}
+  someMin = {mMinI, mMinF64}
 
 proc isValue(n: PNode): bool = n.kind in {nkCharLit..nkNilLit}
 proc isLocation(n: PNode): bool = not n.isValue
@@ -122,7 +123,7 @@ proc neg(n: PNode): PNode =
         let eAsNode = newIntNode(nkIntLit, e.sym.position)
         if not inSet(n.sons[1], eAsNode): s.add eAsNode
       result.sons[1] = s
-    elif lengthOrd(t) < 1000:
+    elif t.kind notin {tyString, tySequence} and lengthOrd(t) < 1000:
       result.sons[1] = complement(n.sons[1])
     else:
       # not ({2, 3, 4}.contains(x))   x != 2 and x != 3 and x != 4
@@ -907,5 +908,5 @@ proc buildProperFieldCheck(access, check: PNode): PNode =
 proc checkFieldAccess*(m: TModel, n: PNode) =
   for i in 1..n.len-1:
     let check = buildProperFieldCheck(n.sons[0], n.sons[i])
-    if m.doesImply(check) != impYes:
+    if check != nil and m.doesImply(check) != impYes:
       message(n.info, warnProveField, renderTree(n.sons[0])); break