Test more posible index values.

Author: dmsc

testsuite/tests/index.bas

@@ -12,11 +12,12 @@ A$="TEST.STRING INDEXING"
 ? A$[2]
 ? A$[2,5]
 ? A$[10]
-for i=1 to 22 : ? i, ">"; A$[i] ; "<" : next i
+? A$[1,256]
+for i=-1 to 22 : ? i, ">"; A$[i] ; "<" : next i
 
 for i=1 to 22 : ? i, ">"; A$[i,2] ; "<" : next i
 
-for i=0 to 22 : ? i, ">"; A$[2,i] ; "<" : next i
+for i=-1 to 22 : ? i, ">"; A$[2,i] ; "<" : next i
 
 for i=1 to 20 : ? i, i*i, str$(i*i)[2,1] : next i
 

testsuite/tests/index.chk

@@ -11,6 +11,9 @@ TEST.
 EST.STRING INDEXING
 EST.S
 NG INDEXING
+TEST.STRING INDEXING
+-1        ><
+0         ><
 1         >TEST.STRING INDEXING<
 2         >EST.STRING INDEXING<
 3         >ST.STRING INDEXING<
@@ -55,6 +58,7 @@ NG INDEXING
 20        >G<
 21        ><
 22        ><
+-1        ><
 0         ><
 1         >E<
 2         >ES<