Closes #9526 guessFileName handle generic content types

components/support/utils/src/main/java/mozilla/components/support/utils/DownloadUtils.kt

@@ -125,6 +125,16 @@ object DownloadUtils {
      */
     private val encodedSymbolPattern = Pattern.compile("%[0-9a-f]{2}|[0-9a-z!#$&+-.^_`|~]", Pattern.CASE_INSENSITIVE)
 
+    /**
+     * Keep aligned with desktop generic content types:
+     * https://searchfox.org/mozilla-central/source/browser/components/downloads/DownloadsCommon.jsm#208
+     */
+    private val GENERIC_CONTENT_TYPES = arrayOf(
+        "application/octet-stream",
+        "binary/octet-stream",
+        "application/unknown"
+    )
+
     /**
      * Guess the name of the file that should be downloaded.
      *
@@ -146,7 +156,11 @@ object DownloadUtils {
         val sanitizedMimeType = sanitizeMimeType(mimeType)
 
         val fileName = if (extractedFileName.contains('.')) {
-            changeExtension(extractedFileName, sanitizedMimeType)
+            if (GENERIC_CONTENT_TYPES.contains(mimeType)) {
+                extractedFileName
+            } else {
+                changeExtension(extractedFileName, sanitizedMimeType)
+            }
         } else {
             extractedFileName + createExtension(sanitizedMimeType)
         }

components/support/utils/src/test/java/mozilla/components/support/utils/DownloadUtilsTest.kt

@@ -107,6 +107,9 @@ class DownloadUtilsTest {
         assertEquals("file.html", DownloadUtils.guessFileName(null, null, "http://example.com/file", "text/html"))
         assertEquals("file.html", DownloadUtils.guessFileName(null, null, "http://example.com/file", "text/html; charset=utf-8"))
         assertEquals("file.txt", DownloadUtils.guessFileName(null, null, "http://example.com/file.txt", "text/html"))
+        assertEquals("file.data", DownloadUtils.guessFileName(null, null, "http://example.com/file.data", "application/octet-stream"))
+        assertEquals("file.data", DownloadUtils.guessFileName(null, null, "http://example.com/file.data", "binary/octet-stream"))
+        assertEquals("file.data", DownloadUtils.guessFileName(null, null, "http://example.com/file.data", "application/unknown"))
     }
 
     @Test

docs/changelog.md

@@ -12,6 +12,10 @@ permalink: /changelog/
 * [Gecko](https://github.com/mozilla-mobile/android-components/blob/master/buildSrc/src/main/java/Gecko.kt)
 * [Configuration](https://github.com/mozilla-mobile/android-components/blob/master/.config.yml)
 
+* **feature-downloads**:
+  * 🚒 Bug fixed [issue #9441](https://github.com/mozilla-mobile/android-components/issues/9441) - Don't ask for redundant system files permission if not required.
+  * 🚒 Bug fixed [issue #9526](https://github.com/mozilla-mobile/android-components/issues/9526) - Downloads with generic content types use the correct file extension.
+
 # 72.0.0
 
 * [Commits](https://github.com/mozilla-mobile/android-components/compare/v71.0.0...v72.0.0)
@@ -26,9 +30,6 @@ permalink: /changelog/
 * **support-base**
   * ⚠️ **This is a breaking change**: Update the signature of `ActivityResultHandler.onActivityResult` to avoid conflict with internal Android APIs.
 
-* **feature-downloads**:
-  * 🚒 Bug fixed [issue #9441](https://github.com/mozilla-mobile/android-components/issues/9441) - Don't ask for redundant system files permission if not required.
-
 * **feature-addons**
   * 🚒 Bug fixed [issue #9484] https://github.com/mozilla-mobile/android-components/issues/9484) - Handle multiple add-ons update that require new permissions.