.. und doch kriegst du die Einblendung "Alter Addon-Typ"?
Ja. Den es wird immer die Datei "{972ce4c6-7e08-4474-a285-3208198ce6fd}.xpi" im Installationsordner "...\browser\extensions" abgelegt wenn der die volle Datei runterlädt und installiert.
Quelltext daraus aus der "install.rdf":
XML
<?xml version="1.0"?>
<!-- This Source Code Form is subject to the terms of the Mozilla Public
- License, v. 2.0. If a copy of the MPL was not distributed with this
- file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:em="http://www.mozilla.org/2004/em-rdf#">
<Description about="urn:mozilla:install-manifest">
<em:id>{972ce4c6-7e08-4474-a285-3208198ce6fd}</em:id>
<em:version>57.0.4</em:version>
<!-- Target Application this theme can install into,
with minimum and maximum supported versions. -->
<em:targetApplication>
<Description>
<em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
<em:minVersion>57.0.4</em:minVersion>
<em:maxVersion>57.0.4</em:maxVersion>
</Description>
</em:targetApplication>
<!-- Front End MetaData -->
<em:name>Default</em:name>
<em:description>The default theme.</em:description>
<!-- Front End Integration Hooks (used by Theme Manager)-->
<em:creator>Mozilla</em:creator>
<em:contributor>Mozilla Contributors</em:contributor>
<!-- Allow lightweight themes to apply to this theme -->
<em:skinnable>true</em:skinnable>
<em:internalName>classic/1.0</em:internalName>
<em:iconURL>chrome://browser/content/default-theme-icon.svg</em:iconURL>
</Description>
</RDF>
In der .xpi-Datei befindet dann nur noch eine "chrome.manifest".
Code
override chrome://browser/skin/feeds/audioFeedIcon.png chrome://browser/skin/feeds/feedIcon.png
override chrome://browser/skin/feeds/audioFeedIcon16.png chrome://browser/skin/feeds/feedIcon16.png
override chrome://browser/skin/feeds/videoFeedIcon.png chrome://browser/skin/feeds/feedIcon.png
override chrome://browser/skin/feeds/videoFeedIcon16.png chrome://browser/skin/feeds/feedIcon16.png
override chrome://browser/skin/page-livemarks.png chrome://browser/skin/feeds/feedIcon16.png
override chrome://browser/skin/toolbarbutton-dropdown-arrow.png chrome://browser/skin/toolbarbutton-dropdown-arrow-win7.png os=WINNT osversion<=6.1
override chrome://global/skin/arrow/arrow-lft-hov.gif chrome://global/skin/arrow/arrow-lft.gif
override chrome://global/skin/arrow/arrow-rit-hov.gif chrome://global/skin/arrow/arrow-rit.gif
override chrome://global/skin/tree/twisty.svg#clsd chrome://global/skin/tree/twisty-preWin10.svg#clsd osversion<=6.3
override chrome://global/skin/tree/twisty.svg#clsd-hover chrome://global/skin/tree/twisty-preWin10.svg#clsd-hover osversion<=6.3
override chrome://global/skin/tree/twisty.svg#clsd-hover-rtl chrome://global/skin/tree/twisty-preWin10.svg#clsd-hover-rtl osversion<=6.3
override chrome://global/skin/tree/twisty.svg#clsd-rtl chrome://global/skin/tree/twisty-preWin10.svg#clsd-rtl osversion<=6.3
override chrome://global/skin/tree/twisty.svg#open chrome://global/skin/tree/twisty-preWin10.svg#open osversion<=6.3
override chrome://global/skin/tree/twisty.svg#open-hover chrome://global/skin/tree/twisty-preWin10.svg#open-hover osversion<=6.3
override chrome://global/skin/tree/twisty.svg#open-hover-rtl chrome://global/skin/tree/twisty-preWin10.svg#open-hover-rtl osversion<=6.3
override chrome://global/skin/tree/twisty.svg#open-rtl chrome://global/skin/tree/twisty-preWin10.svg#open-rtl osversion<=6.3
override chrome://mozapps/skin/xpinstall/xpinstallItemGeneric.png chrome://mozapps/skin/extensions/extensionGeneric.svg