1 files changed, 31 insertions, 7 deletions
diff --git a/app/src/main/java/org/terst/feedreader/data/CachedExtraction.kt b/app/src/main/java/org/terst/feedreader/data/CachedExtraction.kt
index 313d467..3a791cc 100644
--- a/app/src/main/java/org/terst/feedreader/data/CachedExtraction.kt
+++ b/app/src/main/java/org/terst/feedreader/data/CachedExtraction.kt
@@ -1,6 +1,7 @@
 package org.terst.feedreader.data
 
 import org.terst.feedreader.readability.ConsentNotice
+import org.terst.feedreader.readability.UnrenderedTex
 
 /** What a cached `articles.extractedContent` value turned out to be worth. */
 data class CachedExtraction(
@@ -11,12 +12,24 @@ data class CachedExtraction(
      * show and should extract again -- the cache is the reason the article looked
      * broken, so dropping it silently would just leave a blank reader.
      */
-    val discardedConsentNotice: Boolean
-)
+    val discardedConsentNotice: Boolean,
+    /**
+     * True when a cached extraction holding raw TeX source was thrown away -- it was
+     * extracted before extraction knew how to render maths (see [UnrenderedTex]).
+     */
+    val discardedUnrenderedTex: Boolean = false
+) {
+    /**
+     * True when something was thrown away, whatever it was: there is nothing to show and
+     * the caller has to extract again.
+     */
+    val discarded: Boolean get() = discardedConsentNotice || discardedUnrenderedTex
+}
 
 /**
  * Reads a cached extraction, dropping it if it is the site's cookie/consent notice
- * rather than the article.
+ * rather than the article, or if it is an older extraction whose maths never got
+ * rendered.
  *
  * Needed because the extractor's own guard can only keep a bad extraction from
  * being written in future. The reported bug ("reader mode just extracts cookie
@@ -33,9 +46,20 @@ suspend fun loadCachedExtraction(
     cached: String?,
     clearCache: suspend () -> Unit
 ): CachedExtraction {
-    if (!ConsentNotice.looksLikeConsentNotice(cached)) {
-        return CachedExtraction(content = cached, discardedConsentNotice = false)
-    }
+    val discard = when {
+        ConsentNotice.looksLikeConsentNotice(cached) ->
+            CachedExtraction(content = null, discardedConsentNotice = true)
+        // Same shape of problem, different cause: this one was extracted before extraction
+        // rendered maths, so it holds the TeX source the page shipped.
+        UnrenderedTex.looksLikeUnrenderedTex(cached) ->
+            CachedExtraction(
+                content = null,
+                discardedConsentNotice = false,
+                discardedUnrenderedTex = true
+            )
+        else -> null
+    } ?: return CachedExtraction(content = cached, discardedConsentNotice = false)
+
     clearCache()
-    return CachedExtraction(content = null, discardedConsentNotice = true)
+    return discard
 }