Fix some problems in test code detected by cppcheck.

FossilOrigin-Name: c9ff4ca4a0b44bbb8d6676144ddf77b04426e619

src/test1.c

@@ -338,7 +338,7 @@ static int test_exec_hex(
   int rc, i, j;
   char *zErr = 0;
   char *zHex;
-  char zSql[500];
+  char zSql[501];
   char zBuf[30];
   if( argc!=3 ){
     Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0], 
@@ -347,7 +347,7 @@ static int test_exec_hex(
   }
   if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
   zHex = argv[2];
-  for(i=j=0; i<sizeof(zSql) && zHex[j]; i++, j++){
+  for(i=j=0; i<(sizeof(zSql)-1) && zHex[j]; i++, j++){
     if( zHex[j]=='%' && zHex[j+2] && zHex[j+2] ){
       zSql[i] = (testHexToInt(zHex[j+1])<<4) + testHexToInt(zHex[j+2]);
       j += 2;