fix: Do not fail to send images with wrong extensions

Try to guess the image format based on its content first.

Co-authored-by: iequidoo <dgreshilov@gmail.com>

src/chat.rs

@@ -7528,4 +7528,27 @@ mod tests {
         assert_eq!(a1_broadcast_chat.get_name(), "Broadcast list 42");
         Ok(())
     }
+
+    /// Tests sending JPEG image with .png extension.
+    ///
+    /// This is a regression test, previously sending failed
+    /// because image was passed to PNG decoder
+    /// and it failed to decode image.
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_jpeg_with_png_ext() -> Result<()> {
+        let alice = TestContext::new_alice().await;
+        let bob = TestContext::new_bob().await;
+
+        let bytes = include_bytes!("../test-data/image/screenshot.jpg");
+        let file = alice.get_blobdir().join("screenshot.png");
+        tokio::fs::write(&file, bytes).await?;
+        let mut msg = Message::new(Viewtype::Image);
+        msg.set_file(file.to_str().unwrap(), None);
+
+        let alice_chat = alice.create_chat(&bob).await;
+        let sent_msg = alice.send_msg(alice_chat.get_id(), &mut msg).await;
+        let _msg = bob.recv_msg(&sent_msg).await;
+
+        Ok(())
+    }
 }