From 88f3b1d99f6601b0ada29d77dfb771d6c9885163 Mon Sep 17 00:00:00 2001
From: Hans Raaf <hara@oderwat.de>
Date: Wed, 18 Feb 2015 18:42:45 +0100
Subject: [PATCH 1/2] Fixing toHex() to not wrap for long lens.

If you specify a len like 32 toHex() will repeat the given value in the
output. Besides that I believe my implementation is easier and seems not
to change how negative numbers are handled. I also handle the case of
wrapping negative number beyond BiggestInt to "do it right".
---
 lib/pure/strutils.nim | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/pure/strutils.nim b/lib/pure/strutils.nim
index 17e0b9e632..39f468ee3b 100644
--- a/lib/pure/strutils.nim
+++ b/lib/pure/strutils.nim
@@ -395,11 +395,13 @@ proc toHex*(x: BiggestInt, len: int): string {.noSideEffect,
   const
     HexChars = "0123456789ABCDEF"
   var
-    shift: BiggestInt
+    n = x
   result = newString(len)
   for j in countdown(len-1, 0):
-    result[j] = HexChars[toU32(x shr shift) and 0xF'i32]
-    shift = shift + 4
+    result[j] = HexChars[n and 0xF]
+    n = n shr 4
+    # handle negative overflow
+    if n == 0 and x < 0: n = -1
 
 proc intToStr*(x: int, minchars: int = 1): string {.noSideEffect,
   rtl, extern: "nsuIntToStr".} =

From a471b3c87fa3be6f9a5042ba8b814762118d4a07 Mon Sep 17 00:00:00 2001
From: Hans Raaf <hara@oderwat.de>
Date: Wed, 18 Feb 2015 19:02:38 +0100
Subject: [PATCH 2/2] Added test for toHex().

---
 tests/stdlib/tstrutil.nim | 51 +++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 24 deletions(-)

diff --git a/tests/stdlib/tstrutil.nim b/tests/stdlib/tstrutil.nim
index da65d1f89e..ce9094bc09 100644
--- a/tests/stdlib/tstrutil.nim
+++ b/tests/stdlib/tstrutil.nim
@@ -2,18 +2,18 @@ discard """
   file: "tstrutil.nim"
   output: "ha/home/a1xyz/usr/bin"
 """
-# test the new strutils module
-
-import
-  strutils
-
-proc testStrip() =
-  write(stdout, strip("  ha  "))
-
-proc main() = 
-  testStrip()
-  for p in split("/home/a1:xyz:/usr/bin", {':'}):
-    write(stdout, p)
+# test the new strutils module
+
+import
+  strutils
+
+proc testStrip() =
+  write(stdout, strip("  ha  "))
+
+proc main() = 
+  testStrip()
+  for p in split("/home/a1:xyz:/usr/bin", {':'}):
+    write(stdout, p)
 
 proc testDelete = 
   var s = "0123456789ABCDEFGH"
@@ -25,25 +25,28 @@ proc testDelete =
   assert s == "1236789ABCDEFG"
 
 testDelete()  
-    
+    
 assert(insertSep($1000_000) == "1_000_000")
 assert(insertSep($232) == "232")
 assert(insertSep($12345, ',') == "12,345")
 assert(insertSep($0) == "0")
-
-assert(editDistance("prefix__hallo_suffix", "prefix__hallo_suffix") == 0)
-assert(editDistance("prefix__hallo_suffix", "prefix__hallo_suffi1") == 1)
-assert(editDistance("prefix__hallo_suffix", "prefix__HALLO_suffix") == 5)
-assert(editDistance("prefix__hallo_suffix", "prefix__ha_suffix") == 3)
-assert(editDistance("prefix__hallo_suffix", "prefix") == 14)
-assert(editDistance("prefix__hallo_suffix", "suffix") == 14)
-assert(editDistance("prefix__hallo_suffix", "prefix__hao_suffix") == 2)
+
+assert(editDistance("prefix__hallo_suffix", "prefix__hallo_suffix") == 0)
+assert(editDistance("prefix__hallo_suffix", "prefix__hallo_suffi1") == 1)
+assert(editDistance("prefix__hallo_suffix", "prefix__HALLO_suffix") == 5)
+assert(editDistance("prefix__hallo_suffix", "prefix__ha_suffix") == 3)
+assert(editDistance("prefix__hallo_suffix", "prefix") == 14)
+assert(editDistance("prefix__hallo_suffix", "suffix") == 14)
+assert(editDistance("prefix__hallo_suffix", "prefix__hao_suffix") == 2)
 
 assert "/1/2/3".rfind('/') == 4
 assert "/1/2/3".rfind('/', 1) == 0
 assert "/1/2/3".rfind('0') == -1
-
-main()
-#OUT ha/home/a1xyz/usr/bin
+
+assert(toHex(100i16, 32) == "00000000000000000000000000000064")
+assert(toHex(-100i16, 32) == "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF9C")
+
+main()
+#OUT ha/home/a1xyz/usr/bin