Fix scroll regression and feed-setting reset on re-import

- ReaderScreen: the direction-ratio gesture rewrite (using a generic,
  non-oriented detectDragGestures to compute a custom dx/dy ratio) broke
  scrolling entirely -- reported live as "the article view doesn't scroll
  at all anymore." Root cause: detectDragGestures' touch-slop detection is
  isotropic (claims the first bit of movement in ANY direction before it
  knows which way the gesture is going), unlike detectHorizontalDragGestures
  which is orientation-aware and simply never engages for a vertical-
  dominant drag. Reverted to detectHorizontalDragGestures, keeping the
  distance-based (not edge-anchored) commit threshold from the previous
  fix. Verified live: a long article now scrolls properly on a diagonal
  swipe, and a deliberate horizontal swipe still changes pages.

- AddFeedScreen: both the OPML import and single-URL add built a bare
  FeedEntity(id, title, siteUrl) and upserted it (REPLACE) even when a
  feed with that id already existed -- silently wiping readerModeDisabled
  (and etag/lastModified/lastError) back to defaults on every re-import or
  re-add. This is exactly what made a feed's reader-mode toggle appear not
  to persist. Now preserves the existing row via .copy() when one exists.
  Verified live: set kottke.org's readerModeDisabled=1, re-imported the
  same OPML file (107 feeds), and confirmed the flag was still 1 afterward.

1 files changed, 15 insertions, 4 deletions

diff --git a/app/src/main/java/org/terst/feedreader/ui/AddFeedScreen.kt b/app/src/main/java/org/terst/feedreader/ui/AddFeedScreen.kt
index 5d19c90..066d8d9 100644
--- a/app/src/main/java/org/terst/feedreader/ui/AddFeedScreen.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/AddFeedScreen.kt
@@ -63,7 +63,14 @@ fun AddFeedScreen(onDone: () -> Unit) {
             // as some larger number even though upsert already collapses them to one row each.
             val uniqueFeeds = imported.distinctBy { it.xmlUrl }
             for (feed in uniqueFeeds) {
-                db.feedDao().upsert(FeedEntity(id = feed.xmlUrl, title = feed.title, siteUrl = feed.htmlUrl))
+                // upsert() REPLACEs the whole row -- for a feed that's already subscribed,
+                // building a bare FeedEntity here would silently wipe readerModeDisabled
+                // (and etag/lastModified/lastError) back to defaults on every re-import.
+                // Preserve the existing row's other fields; only title/siteUrl come from OPML.
+                val existing = db.feedDao().getById(feed.xmlUrl)
+                val entity = existing?.copy(title = feed.title, siteUrl = feed.htmlUrl ?: existing.siteUrl)
+                    ?: FeedEntity(id = feed.xmlUrl, title = feed.title, siteUrl = feed.htmlUrl)
+                db.feedDao().upsert(entity)
             }
             FeedFetchWorker.fetchNow(context)
             status = "Imported ${uniqueFeeds.size} feed(s)"
@@ -145,9 +152,13 @@ private suspend fun addFeedByUrl(context: android.content.Context, db: AppDataba
                 if (!it.isSuccessful) return@withContext "Couldn't fetch feed: HTTP ${it.code}"
                 val body = it.body ?: return@withContext "Empty response"
                 val parsed = FeedParser.parse(body.byteStream())
-                db.feedDao().upsert(
-                    FeedEntity(id = feedUrl, title = parsed.title.ifBlank { feedUrl }, siteUrl = parsed.siteUrl)
-                )
+                // Same REPLACE-wipes-other-fields concern as the OPML import path.
+                val existing = db.feedDao().getById(feedUrl)
+                val entity = existing?.copy(
+                    title = parsed.title.ifBlank { feedUrl },
+                    siteUrl = parsed.siteUrl ?: existing.siteUrl
+                ) ?: FeedEntity(id = feedUrl, title = parsed.title.ifBlank { feedUrl }, siteUrl = parsed.siteUrl)
+                db.feedDao().upsert(entity)
             }
             FeedFetchWorker.fetchNow(context)
             "Added"