don't delete rows when changing size of CycleStorage to less (bug 4172)

Utilities/JrnTests/JrnTest.cc

@@ -257,6 +257,7 @@ bool testJournal1(void)
 		return false;
 	}
 	k = 0;
+	printf("size changed to 33000 rows (increased)\n");
 	j.setSize(33000);
 	TableBlockStorage t("big_file.test", 4, 40, 100, 5,28,0);
 	printf("test of 2 classes working in 1 file together\n");
@@ -319,8 +320,9 @@ bool testJournal1(void)
 
 	if(!reOpen()) return false;
 
+	printf("size changed back to 32000 rows\n");
 	j.setSize(32000);
-	for(i=0;i<32000;i++)
+	for(i=0;i<20;i++)
 	{
 		if(j.readRow(i,str))
 		{
@@ -328,11 +330,13 @@ bool testJournal1(void)
 			k++;
 		}
 	}
-	if( k>0 )
+	if(k != 10)
 	{
 		delete str;
 		return false;
 	}
+
+	k = 0;
 	delete str;
 	return true;
 }

src/Various/CycleStorage.cc

@@ -408,8 +408,15 @@ bool CycleStorage::setSize(int count)
 
 	if(count<size)
 	{
+		if( head>count-1 )
+		{
+			head = 0;
+			tail = count - 1;
+		}
+		if( tail>count-1 )
+			tail = count - 1;
 		size=count;
-		return delAllRows();
+		return true;
 	}
 
 	int num = count - size;