Qt app crashes when trying to open Word doc that is already opened

[bobbayribs]

Hi all,

I have an app that opens Word docs, parses them, and saves them to text file. Everything works great, except when the Word doc is already opened. Then a popup opens:

File In Use
Do you want to:
Open a Read Only copy
Create a local copy and merge your changes later
Receive notification when the original copy is available

And my app hangs and crashes.

How can I detect a word doc is already opened? Then I just would output an error message, skip opening, and parsing that particular word doc.

my_app = new QAxObject("Word.Application", this);
    QAxObject* my_docs = my_app->querySubObject("Documents");
 
    //Open docxFile
    QString filename(docxFile);
    QVariant confirmconversions(false);
    QVariant readonly(false);
    QVariant addtorecentfiles(false);
    QVariant passworddocument("");
    QVariant passwordtemplate("");
    QVariant revert(false);
 
    QAxObject* doc = my_docs->querySubObject("Open(const QVariant&, const QVariant&,const QVariant&, const QVariant&, const QVariant&, const QVariant&,const QVariant&)", filename, confirmconversions, readonly, addtorecentfiles, passworddocument, passwordtemplate,	revert);
 
    //Pull out active document object
    QAxObject* active_doc = my_app->querySubObject("ActiveDocument");

my_app = new QAxObject("Word.Application", this);
    QAxObject* my_docs = my_app->querySubObject("Documents");

    //Open docxFile
    QString filename(docxFile);
    QVariant confirmconversions(false);
    QVariant readonly(false);
    QVariant addtorecentfiles(false);
    QVariant passworddocument("");
    QVariant passwordtemplate("");
    QVariant revert(false);

    QAxObject* doc = my_docs->querySubObject("Open(const QVariant&, const QVariant&,const QVariant&, const QVariant&, const QVariant&, const QVariant&,const QVariant&)", filename, confirmconversions, readonly, addtorecentfiles, passworddocument, passwordtemplate,	revert);

    //Pull out active document object
    QAxObject* active_doc = my_app->querySubObject("ActiveDocument");

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Thanks!

[Lesiok]

All functions return pointer to QAxObject. You have to test if returned pointer is not null.

[bobbayribs]

Cannot test for null pointer because the "File In Use" popup window appears before a null pointer is returned:

my_app: QAxObject(0x4ec1520)
my_docs: QAxObject(0x4ec1bf8)
//"File In Use" popup window appears here. This is the querySubObject("Open...) command.
doc: QObject(0x0)

[d_stranz]

If you want to open it read-only, why are you setting the readonly QVariant to "false"? That's likely the source of your file in use error.

And I echo Lesiok's comment: You must test pointers for non-null before dereferencing them (i.e. using them to call another method). It's a guaranteed crash if get one and you don't test it.

[bobbayribs]

Thank you d_stranz, I set read-only to true and everything works fine now!

Since I was opening the doc file and saving it as a text file, I thought it couldn't be read-only, but I was wrong.

If saving a file, shouldn't one needs read/write permissions on the doc? Anyway, thank you for the help!!