fixes #11369 (#11381)

lib/pure/strutils.nim

@@ -892,14 +892,14 @@ proc toBin*(x: BiggestInt, len: Positive): string {.noSideEffect,
     doAssert b.toBin(8) == "00000001"
     doAssert b.toBin(9) == "100000001"
   var
-    mask: BiggestInt = 1
+    mask = BiggestUInt 1
-    shift: BiggestInt = 0
+    shift = BiggestUInt 0
   assert(len > 0)
   result = newString(len)
   for j in countdown(len-1, 0):
-    result[j] = chr(int((x and mask) shr shift) + ord('0'))
+    result[j] = chr(int((BiggestUInt(x) and mask) shr shift) + ord('0'))
-    shift = shift + 1
+    inc shift
-    mask = mask shl 1
+    mask = mask shl BiggestUInt(1)
 
 proc toOct*(x: BiggestInt, len: Positive): string {.noSideEffect,
   rtl, extern: "nsuToOct".} =
@@ -917,14 +917,14 @@ proc toOct*(x: BiggestInt, len: Positive): string {.noSideEffect,
     doAssert b.toOct(3) == "001"
     doAssert b.toOct(5) == "01001"
   var
-    mask: BiggestInt = 7
+    mask = BiggestUInt 7
-    shift: BiggestInt = 0
+    shift = BiggestUInt 0
   assert(len > 0)
   result = newString(len)
   for j in countdown(len-1, 0):
-    result[j] = chr(int((x and mask) shr shift) + ord('0'))
+    result[j] = chr(int((BiggestUInt(x) and mask) shr shift) + ord('0'))
-    shift = shift + 3
+    inc shift, 3
-    mask = mask shl 3
+    mask = mask shl BiggestUInt(3)
 
 proc toHex*(x: BiggestInt, len: Positive): string {.noSideEffect,
   rtl, extern: "nsuToHex".} =

tests/stdlib/tstrutil.nim

@@ -308,6 +308,13 @@ assert(' '.repeat(0) == "")
 assert(" ".repeat(0) == "")
 assert(spaces(0) == "")
 
+# bug #11369
+
+var num: int64 = -1
+assert num.toBin(64) == "1111111111111111111111111111111111111111111111111111111111111111"
+assert num.toOct(24) == "001777777777777777777777"
+
+
 # bug #8911
 when true:
   static: