MS HH Viewer doesn't show pictures, styles of not elevated TC CHM Help

[DrShark]

On Windows 7 32 bit system with Internet Explorer 11 I currently use I can confirm the issue, reported also on many Internet sites: FreeCommander forum, Microsoft Answers & TechNet: 1, 2, 3, Superuser.com) which also applies to Total Commander CHM help file: if to stat TC without elevation and call help with F1, HH Viewer shows help pages with only white background and black text style (even if TC's dark help CHM is used, though in "full dark" edition, the Table of Content in left HH Viewer panel is dark with white text), and pictures aren't shown, the white on black cross sign (x) is shown as their placeholder. Basically it looks like black+white high contrast theme is applied to the page, and threre are no pictures. As mentioned in some discussions linked above, after F5 or Options->Refresh (but not page context menu->Refresh) in HTML Viewer window it shows the page in correct way with all the pictures and styles applied.

My guess that is has something to do with Intrenet Explorer zone restrictions (which influence on TC Help first time discussed on this forum here) applied either to HTML Help or whole IE and all the apps that use its engie, because for the pages of chm file opened in not elevated IE using its:// or mk:@msitstore:// URLs refresh with F5 is also required to show pictures and use page styles (AFAIR the similar thing happened only with pages opened using mk:@msitstore:// in IE on my Vista PC, but it's not working now, so I cannot check it). Maybe it is not related to CHM issue directly, but not elevaited IE here also cannot download files and doesn't apply UserCSS. But for the pages in Internet, like http://ghisler.ch/help/, it shows pictures and uses page styles. Eleveted IE and HH Viever don't have mentioned problems.

It would be nice to find out a reliable solution for this issue (the suggestion from discussions above to remove the read only attribute from INetCache folder is not achievable on my system because there is no such folder here; and I don't have any subkeys or parameters under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ in registry, so I guess some defaults are used).

Meannwhile I think it's worth considering to add a small note in Total Commander CHM file that if user doesn't see pictures in help, one should try Options->Refresh menu or F5 key.

[ghisler(Author)]

I only saw this happening when downloading the CHM from our homepage and then opening the ZIP with Explorer. The file is then marked as insecure and doesn't run scripts and doesn't show photos. You should be able to remove this insecure status via properties dialog.

[DrShark]

No, CHM files don't have Zone.Identifier ADS here, so there must be other reason for this problem...

[ghisler(Author)]

Are they located on an UNC share or network drive? Then the same happens.

[DrShark]

Are they located on an UNC share or network drive? Then the same happens.

No, TC CHM files are in %COMMANDER_PATH% (c:\totalcmd\).

[petermad]

Is this of any help: https://support.microsoft.com/en-us/help/896358/ms05-026-a-vulnerability-in-html-help-could-allow-remote-code-executio

[DrShark]

So far I couldn't solve the issue on Internet Explorer side - I tried to set IE's secutiry zone for current user the same as it's defined for PC (in HKLM), and even set its level to less restricted, but it didn't help.

Anyway, in this case it seems there is still a way to make pictures appear on CHM side.

I found the CHM file where in the HTML pages the paths to images are referenced to relative location outside of CHM itself.
In HTML source it looks like:

Code: Select all

<script language="JScript">
document.write('<img alt="" style="padding:1px" src="file:///'+location.href.substring((location.href.search(/:/)==2)?14:7,location.href.lastIndexOf("\\")+1)+
'images\\picture.png" />');
</script>

So if we have the help.chm in .\somedir\, and the picture.png in .\somedir\images\, with above code HH Viewer uses file:/// URL instead of mk:@MSITStore: one for picture path, and shows it immediately. Maybe it's possible to use CSS outside of CHM the same way, so HH Viewer will apply it too. but I'm not sure if it's possible to make HH Viewer use relative file:/// URLs for resources like images and styles without JScript.

So basically, if to refer the resources in the CHM in above way, the help could be distributed as the main CHM file (which has only HTML files with text) + all the pictures, and maybe .css as separate files all inside of ZIP archive (in case of TC's help, plugint.inf may be included there too to install the help by entering archive in TC). Such help will use a bit more of disk space because external resources are not compressed by CHM, but in case of TC's help it seems this will add less than 200 kB compared to current size of TOTALCMD.CHM.