In the Wikipedia Beta Android app,
# Visit the [[ https://en.m.wikipedia.org/wiki/Moth | Moth ]] article.
# Click on [[ https://en.m.wikipedia.org/wiki/Crepuscular | Crepuscular ]]
Result:
A nifty Link preview appears at the bottom of the screen and shows
> Crepuscular
> '''Crepuscular''' animals are those that are active primarily during twilight.
> ==Etymology and usageEdit
> ==The word ''crepuscular'' derives from the Latin ''crepusculum'' ("twilight").
Expected result: no stray "Edit" text.
Looking at [[ https://github.com/wikimedia/apps-android-wikipedia/blob/HEAD/wikipedia/src/main/java/org/wikipedia/page/linkpreview/PreviewFetchTask.java | PreviewFetchTask.java]] (be afraid :) ), I think the API request ([[ https://en.wikipedia.org/wiki/Special:ApiSandbox#action=query&prop=extracts&format=json&exchars=512&explaintext=&titles=Crepuscular&redirects= | see/run a simplified version in ApiSandbox]]) is requesting the (text)[[ https://en.wikipedia.org/w/api.php?action=help&modules=query+extracts | extracts ]] property with parameters `exchars=512 explaintext= `; such an API request returns
> "extract": "Crepuscular animals are those that are active primarily during twilight (i.e., dawn and dusk).\n\n\n== Etymology and usageEdit ==\nThe word crepuscular derives from the Latin crepusculum (\"twilight\"). Its sense accordingly //<more text>//"
The presence of the word "Edit" seems like a bug in extension TextExtracts. The Android app's display of the `==` of the section headings also seems like a bug in its parsing. (The presence of `==` wiki markup for section headings in the API response is as intended, since `exsectionformat` determines how to format sections in plaintext mode and it defaults to "Wikitext-style formatting".)