Tuesday, November 18, 2008

Weird Bug While Porting Textml Server Code from JSP to ASP.NET

This morning I was porting an old search results page accessing Textml Server from JSP to ASP.NET. One feature implemented there is search within results. We execute this by storing the original query in the session and then, when a user asks to search within results, we pull it out and re-run it so the second query can reference the first.

We have a line like this in the JSP page...
IxiaResultSpace originalResults = 
...followed by a few lines later by a line like this...
"<include TYPE=\"ResultSpace\">" + sessionID + "-ALL</include>"
All was well.

The logic of the page overall is more than a bit wonky, but we decided to port first and revise later. When done, I was getting an error that said

"vrn2nc55cxej5knnemwyzvqv-ALL is not a valid ResultSpace include /query/andkey/include at Ixiasoft.TextmlServer.ResultSpace.ExecuteQuery() at Ixiasoft.TextmlServer.ResultSpace.get_Count() at searchresults.RunSearch() in c:\Greenwood Web Sites\devsite\searchresults.aspx.cs:line 357."

What's that now?

After some trips through the debugger, poking around the documentation and some googling (no one blogs on this thing) I went back to the old method of just writing out strings to the page. Nothing jumped out as an error and nothing worked.

By sheer chance, I decided to see what the string value of the original query was so I added...
string originalQuery = originalResults.TextmlQuery;
...to the page with the intent of displaying it somewhere for review and suddenly the error stopped being thrown and the code functioned as expected. After making sure I made no other changes I tested it again. I commented out that line and the error was thrown. I put the line back in and the page ran fine. A co-worker asked if the Count property forced it work as well and it does.

I can't explain this one.

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