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<TITLE>Bug in ContentList.addAll(int,Collection)</TITLE>
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<P><FONT SIZE=2>Hi all. In my performance perusal, I have identified a probable bug in the above method.</FONT>
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<P><FONT SIZE=2>The method has the following code:</FONT>
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<P><FONT SIZE=2> int count = 0;</FONT>
<BR><FONT SIZE=2> try {</FONT>
<BR><FONT SIZE=2> Iterator i = collection.iterator();</FONT>
<BR><FONT SIZE=2> while (i.hasNext()) {</FONT>
<BR><FONT SIZE=2> Object obj = i.next();</FONT>
<BR><FONT SIZE=2> add(index + count, obj);</FONT>
<BR><FONT SIZE=2> count++;</FONT>
<BR><FONT SIZE=2> }</FONT>
<BR><FONT SIZE=2> }</FONT>
<BR><FONT SIZE=2> catch (RuntimeException exception) {</FONT>
<BR><FONT SIZE=2> for (int i = 0; i < count; i++) {</FONT>
<BR><FONT SIZE=2> remove(index + i);</FONT>
<BR><FONT SIZE=2> }</FONT>
<BR><FONT SIZE=2> throw exception;</FONT>
<BR><FONT SIZE=2> }</FONT>
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<P><FONT SIZE=2>Which implies that IF there was a problem during the add, the added elements will be removed.</FONT>
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<P><FONT SIZE=2>Unfortunately, the remove(index + i) will do the wrong thing.</FONT>
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<P><FONT SIZE=2>Basically, the remove method already shifts all the subsequent data "left", so, for example,</FONT>
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<P><FONT SIZE=2>if 2 elements (Element A, B, and C) are added in the addAll, at index 4 in the element list abcdefg to get the desired list:</FONT></P>
<P><FONT SIZE=2>abcdABCefg</FONT>
<BR><FONT SIZE=2>but element C failed, then the "count" will be 2, and the lsit will actually be:</FONT>
<BR><FONT SIZE=2>abcdEBefg</FONT>
<BR><FONT SIZE=2>The first iteration of the remove will make the list:</FONT>
<BR><FONT SIZE=2>abcdBefg</FONT>
<BR><FONT SIZE=2>and the second will make it:</FONT>
<BR><FONT SIZE=2>abcdBgf.</FONT>
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<P><FONT SIZE=2>The remove lines should be:</FONT>
<BR><FONT SIZE=2> for (int i = 0; i < count; i++) {</FONT>
<BR><FONT SIZE=2> remove(index);</FONT>
<BR><FONT SIZE=2> }</FONT>
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<P><FONT SIZE=2>Rolf</FONT>
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