Microsoft KB Archive/151092

= PRB: Mismatched Pushjmp/Popjmp Call Message from Modify Form =

Article ID: 151092

Article Last Modified on 10/15/2003

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APPLIES TO


 * Microsoft Visual FoxPro 3.0b for Macintosh
 * Microsoft Visual FoxPro 3.0b Standard Edition

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This article was previously published under Q151092



SYMPTOMS
When you load a Visual FoxPro form for editing, the process stops before the form appears on the Visual FoxPro desktop and an error dialog box appears stating:

"Mismatched pushjmp/popjmp call"

Clicking the OK button causes the Visual FoxPro session to terminate. The subsequent action depends on the operating system.

In Windows 95, the user is sent back to the Windows desktop. However, the Visual FoxPro session remains hidden, but does show in the Windows 95 task list if you press ALT+TAB, and presents a small, modal dialog box when Visual FoxPro for Windows 3.0b is restarted. This dialog box appears behind the Visual FoxPro Desktop of the newer session, remaining hidden until the second Visual FoxPro session is terminated.

In the Windows NT operating system environment, the same error message appears, and Visual FoxPro 3.0b is terminated with no residual processes.

In the Windows for Workgroups and the Windows 3.1x operating systems, the error message is the same. Visual FoxPro is terminated and Windows is locked so the user must use a "Cold" boot, pushing the reset button or power off/on, to resume normal operations.

In Visual FoxPro for the Macintosh version 3.0b, the error message returned states

"Error loading file - Row Source Type - Record . Property value is out of bounds"

where  is the row number of the offending control in the .scx table.



CAUSE
This behavior occurs when the form has been saved with the Row Source property of a Listbox or ComboBox containing any command or reference which has more than 254 characters. An example of a command that is too long is an SQL Select command that has too many characters in the command expression.

While the limit for a command length in Visual FoxPro for Windows 3.0 is 8092 characters, the limit is only 254 characters when the command is a property of a control on a form.

If the RowSourceType property is "3 - SQL Statement" for either a Listbox or Combobox control, the actual SQL SELECT command can be keyed into the RowSource property in the Property Window.

The Property window of the form limits the number of characters keyed into the box to 254. However, the acceptable length of the string comprising the SELECT-SQL statement is 253 bytes.

When an incorrect SELECT is the RowSource of the control, the form is saved and then restored to the desktop with a MODIFY FORM or a DO FORM. Visual FoxPro then presents an information dialog box stating:

"Mismatched pushjmp/popjmp call"



WORKAROUND
To work around this behavior, reduce the length of the SQL SELECT statement. If you have a copy of Visual FoxPro for Windows 3.0, the form can be modified, the RowSource SELECT statement modified, and the form can be loaded for editing and/or execution in Visual FoxPro for Windows release 3.0b.

If the method above is unavailable, the .scx table can be loaded into a work area with a USE command and then browsed. Each control on the form is described in a row. The control name is located in a memo field named "Objname", and the actual SELECT statement is in a memo field named "Properties." When the incorrect statement is found, it can be edited to the correct length and then saved.



STATUS
This behavior is by design.



Steps to Reproduce Behavior
 In the Visual FoxPro Command window, type MODIFY FORM testerr . From the Form Control toolbar, select Listbox ,and click the form to place a listbox. Click the right mouse button on the listbox, and select Properties from the Context menu. From the Property menu, choose RowSourceType, and select "3 - SQL statement." Click the RowSource property in the row above the RowSourceType.</li>  In the Property window, type "SELECT . . . SQL command." The program limits the statement to 254 bytes, truncating the last word at DESCEND, as follows: SELECT ".." + PADR(CDOW(td_end),12) + DTOC(td_end) ; + "-.-" + PADR( ALLTRIM(STR( kl_prt_ct )) ;     + " LEADS ",10) ; +IIF(kl_type="P","..Printed "," UNPRINTED") ; AS day, td_end,kl_type ; FROM trakdate, keylead ; WHERE DTOS(td_end)=keylead.kl_code ; INTO CURSOR te ; ORDER BY td_date DESCENDING </li> From the File menu, select Save, and then close the form.</li> In the Command window, enter the command "MODIFY FORM testerr."</li></ol>

Additional query words: VFoxWin error freeze terminate list box combo

Keywords: KB151092

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