According to the documentation, the first parameter of the Reply (and ReplyAll, and Forward) events on a MailItem event in Outlook is “the new item being sent in response to the original message”.

Uh, no. At least in VSTO; not sure about VBA, but I cannot see how it could be different there given that VSTO is a wrapper around the same COM interfaces. The argument is the original item that is being responded to:

void OnReply(object Response, ref bool Cancel)
{
    Cancel = false;

    if (Response is Outlook.MailItem item) {
        string html = item.HTMLBody;
        int pos = html.LastIndexOf("</body>");
        item.HTMLBody = html.Insert(pos, "This is the modified item. ");
    }
}

After this handler runs, the original item that was replied to will have the new sentence at the end, while the reply is entirely original. I suppose this means that the response message is created first, and then the event fires with the wrong argument.

Helpfully, though, when using Outlook’s preview/reading pane (whatever its name is this afternoon) the InlineResponse event on the Explorer object actually gets the correct message, i.e. the new one.

After developing a new Outlook VSTO add-in, I noticed that at the first start after installing it (by the MSI method), Outlook would display a trust warning. The add-in is unsigned, but this should still not happen based on my experience from other add-ins.

As it turns out, there are two ways to “grant trust to the solution”:

• Sign the add-in
• Install it into the Program Files directory

The latter presumably works because Office assumes that write access to Program Files is sufficient evidence of administrative intent.

My installation path was C:\Program Files\Some Company\SomeAddin.

Huh. Now what?

…

… oh no, they didn’t …

… yes, they did.

Can you guess?

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OK, a hint. The “Program Files” directory?

S
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Either you have figured it out by now, or are hungry for the solution (because why else would you still be reading this?), so here it is:

The “Program Files” directory they talk about is the same “Program Files” directory that Office is installed in. My scenario involved a .NET assembly compiled to MSIL, so naturally I put it into the 64-bit Program Files directory because that one is more native to the system. The Office installation, however, was still 32-bit, and Outlook came to the (well, partially) unreasonable conclusion that:

"C:\Program Files\" != "C:\Program Files (x86)\"

Therefore the add-in was not installed in the Program Files directory, and therefore not to be trusted by default.

Writing Office add-ins has always been a bit of a dark art because there is not really all that much documentation, and what there is, tends to, let’s say, have been overtaken by events.

This is particularly true where VSTO, the Visual Studio Tools for Office, otherwise known as the .NET wrappers around the COM add-in API, is concerned. Even a seemingly simple task like finding out correct signatures for callback methods can be surprisingly difficult because the authoritative page still only mentions Office 2007, and you can never know what may have changed in the last 13 years. (Wow. Has it been that long?)

OK, enough of the empty complaining. Let’s get to the useful information. Everything below is based on current Office 365 with the latest VSTO version as of today, 10.0.60724.

The loadImage callback

The correct C# signature for the callback method named in <customUI loadImage="LoadImageCallback"> is:

public Bitmap LoadImageCallback(string imageId)

There are various discussions around the Internet on whether this method should return Bitmap or stdole.IPictureDisp, or whether Bitmap works everywhere except Outlook.

Bitmap works everywhere including Outlook.

Namespaces and idQ

When using the idQ attribute to identify controls, you may notice that your callbacks aren’t. Called, that is. This is explained in a paragraph about one-third down the page linked above:

If you use a COM add-in to customize the Fluent UI, the namespace name must be the ProgID of the COM add-in, but the behavior is otherwise the same. When you use a shared add-in, the ProgID is AddInName.Connect. When you use Microsoft Visual Studio 2005 Tools for the 2007 Microsoft Office System (Visual Studio 2005 Tools for Office Second Edition) to create the add-in, the ProgID is the name of the add-in.

(Emphasis mine.)

VSTO is actually older than the W3C recommendation on “Namespaces in XML 1.0”, Second Edition, so I have to admit that the idea did not contradict the spec at the time. (The original recommendation from 1999 mentioned that the intent was to use URIs, but did not yet require it.)

However, I fail to see the reason why the namespace ID must be the add-in’s name, unless it is the result of a very ugly shortcut in the implementation of the “Fluent” UI, i.e. the Ribbon. It would be entirely simple for the host application to associate any string with the add-in whose GetCustomUI() returned the particular bit of XML.

By the way, the “name of the add-in” in the VSTO case above, that the namespace ID has to match, is the name of the subkey of SOFTWARE\Microsoft\Office\...\Addins. In addition to being true empirically, it also matches the non-VSTO case because the only place where the ProgID is involved in the process of loading an add-in is that Registry key.

Daß Versandbenachrichtigungen immer gelogen sind, weil sie im Zweifelsfall dadurch ausgelöst werden, daß der Aufkleber erzeugt wird, ist ja nicht neu. Neu ist, daß jemand die Lüge aus der Überschrift schon im ersten Satz so klar entlarvt.

There is a new Windows 10 “functional update”, so of course we also need new Intel network drivers for our VLANs. Intel have been really laying on the speed this time; three weeks from general availability (of 2004) to a driver release is a new record, I think.

Hey! Great job! Let’s all run and install the new 25.1.1 drivers today!

Unless … you aren’t feeling particularly sentimental about the *-NetAdapter cmdlets, are you? The ones you just got back in 25.0 after creating any VLANs used to break them for the longest time?

You are? Oh. Then I may have a bit of bad news for you.

Yes. They’re gone again; same error as before. Someone forgot to merge the fix branch, I suppose.

What do I hear you say? Is it “Quick! Let everyone know! On the Intel forum where they announced the release and asked for feedback!”, perhaps?

Oh. Then I may have a bit of bad news for you.

You see, the Intel forums have just gone read-only for several days while they are “transitioning to a new platform”, which will also have a new URL.

Great timing. Really great timing.

… and to think it only took me three months to notice that the front page was empty, and only another three to fix that.

Well, Jabra, of course your “Jabra Direct” headset setup application is Chromium based, or whatever enormous rendering engine is en vogue today. After all, the application has at least five pages to show, and ten buttons or so, so clearly you need a full-blown web browser to show this surfeit of UI.

And of course this means that the two-bit application comes in at five processes. Efficiency is for the wimps!

And yes, of course closing the windows only does exactly that, but leaves the five processes running forever, doing God knows what, and with no sign whatsoever of their presence (such as a tray icon or so).

Another entry on the list of sometimes useful applications that nonetheless get installed only when needed and then removed immediately afterwards.

The Python-on-Windows people are at it again. This time they have deliberately broken os.path.expanduser() in 3.8.

Until 3.7, expanduser() treated a tilde at the front of the path given to it the same as a *ix shell, i.e. ‘~/’ was replaced by the current user’s home directory, and ‘~user/’ with that of user user. More specifically, it used the value of the HOME environment variable, or USERPROFILE if the former did not exist, or HOMEDRIVE\HOMEPATH as a final fallback (on NT 3.51, perhaps?).

Then someone complained about that, Python bug #36264, and for some reason unknown to the world, it was decided not to consider HOME anymore.

This (and I’m speaking out of a deep personal animus) was the most misguided decision since splitting the Windows distribution into 22 MSI packages per architecture.

Why?

Because the supposed rationale for the change is that HOME is not a “special” variable on Windows, i.e. it is not something the system/shell cares more about than any other environment variable.

So what? It was documented that it was used by expanduser(), and that is what matters. Explicitly mentioning some behavior in the documentation, without a note that it is an implementation detail subject to change, is what interface contracts are made of.

The documentation does not make any claims that HOME is used because it is of any particularly exalted rank, it simply says it is used. The relevant paragraph could even be read simply as “the user’s home directory, unless overridden with HOME”.

In a particularly cruel twist, the original complainant even pointed out that their problem was actually caused by a bug in MSYS, but the Python-on-Windows maintainer apparently felt that this localized problem with a single tool merited breaking part of the Python standard library for everyone. (The tool was Git, but still …)

Atlassian have made the extremely regrettable decision to stop supporting Mercurial on Bitbucket, suggesting that everyone migrate their repositories to Git. (They say they “considered” developing an automated migrator, but ultimately they decided to wash their hands of the whole affair and just abandon their customers.)

There does not appear to be a viable alternative hosting solution (by which I mean, none of the dozen or so I looked at are any good), and I’m not going to run my own server; I have better things to do with my time.

Unfortunately, this means that a lot of that time I have the aforementioned better things to do with will be spent converting quite a few Mercurial repos to Git, and learning how to use that crime against sanity and humanity, Git.

I have been a user of the excellent TortoiseHg for many years now, but apparently this is now going to change. I hope the project will keep going.

Thanks for nothing, Atlassian.

Microsoft left some things in the Windows 10 1903 release that crept in during development and should have been removed.

• This is called pseudolocalization:

• Something called the “Multiple Provider Notification Application” creates a directory at C:\Service\Trace Files at each boot.

There is certainly a lot more I have not yet encountered.