We sometimes cache page titles using a redirect title as a key and other times using the article's canonical title. This leads to multiple, differing copies of an article being cached, with the copy retrieved when loading from cache depending on the title in the link followed. We should be caching once under the canonical title only.
=== Steps to reproduce
# Search and go to (en) article [[Aurora Plastics Corporation]]
# Click link to [[Monogram Models]] at the end of the lead paragraph and navigate to the article.
# Observe in log: "Writing to cache: Monogram Models"
# Refresh the page
# Observe in log: "Writing to cache: Monogram (company)"
# Close and reopen the app
# Observe in log: "Using page from cache: Monogram Models"
=== Expected results
Page is cached once, using the canonical title to construct the cache key
=== Actual results
The page cache can in principle contain as many copies as there are redirect titles plus the canonical title. The copies can differ. Which you get depends on how you navigated to the page.
=== Stack trace
```
12-08 14:51:38.838 18270-18355/org.wikipedia.dev D/org.wikipedia.page.PageCache$GetPageFromCacheTask: performTask():146: Reading from cache: Monogram Models
12-08 14:51:38.879 18270-18270/org.wikipedia.dev D/org.wikipedia.page.PageDataClient$11: onGetComplete():482: Using page from cache: Monogram Models
...
12-08 14:51:50.346 18270-18323/org.wikipedia.dev D/org.wikipedia.page.PageCache$GetPageFromCacheTask: performTask():146: Reading from cache: Aurora Plastics Corporation
12-08 14:51:50.369 18270-18270/org.wikipedia.dev D/org.wikipedia.page.PageDataClient$11: onGetComplete():482: Using page from cache: Aurora Plastics Corporation
...
12-08 14:53:44.128 18270-18311/org.wikipedia.dev D/org.wikipedia.page.PageCache$AddPageToCacheTask: performTask():84: Writing to cache: Monogram Models
<refresh>
12-08 14:53:50.774 18270-18381/org.wikipedia.dev D/org.wikipedia.page.PageCache$AddPageToCacheTask: performTask():84: Writing to cache: Monogram (company)
...
12-08 14:54:09.166 20509-20620/org.wikipedia.dev D/org.wikipedia.page.PageCache$GetPageFromCacheTask: performTask():146: Reading from cache: Monogram Models
12-08 14:54:09.195 20509-20509/org.wikipedia.dev D/org.wikipedia.page.PageDataClient$11: onGetComplete():482: Using page from cache: Monogram Models
```
=== Environments observed
**App version: ** dev
**Android OS versions:** Nougat
**Device model:** 6P
**Device language:** en