# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1406491268 25200
# Node ID 8dbb2d2522a53b5b1abddef35c53a2d84ba79629
# Parent  14b4e540af2820d9043c39cd0dd6a0afcf0f7d66
Fix a crash in from:withLength when given a negative length. Fix a bug in trim that was causing it to give a negative length to from:withLength

diff -r 14b4e540af28 -r 8dbb2d2522a5 modules/string.tp
--- a/modules/string.tp	Sat Jul 26 15:02:01 2014 -0700
+++ b/modules/string.tp	Sun Jul 27 13:01:08 2014 -0700
@@ -211,6 +211,12 @@
 			start <- bytes
 		}
 		clampedLen <- tocopy num
+		if: clampedLen < 0 {
+			clampedLen <- bytes - clampedLen
+			if: clampedLen < 0 {
+				clampedLen <- 0
+			}
+		}
 		if: start + clampedLen > bytes {
 			clampedLen <- bytes - start
 		}
@@ -293,16 +299,16 @@
 		} do: {
 			start <- start + 1
 		}
-		end <- l
+		end <- l - 1
 		while: {
-			if: end > 0 {
-				b <- byte: end - 1
+			if: end > start {
+				b <- byte: end
 				b = space || b = tab || b = nl || b = cr
 			}
 		} do: {
 			end <- end - 1
 		}
-		from: start withLength: (end - start)
+		from: start withLength: (end + 1 - start)
 	}
 	
 	startsWith? <- :prefix {