fix(media): return an error when content is failed to be parsed as an image

src/service/media/mod.rs

@@ -2,6 +2,7 @@ mod data;
 use std::io::Cursor;
 
 pub use data::Data;
+use ruma::api::client::error::ErrorKind;
 
 use crate::{services, Result};
 use image::imageops::FilterType;
@@ -117,6 +118,7 @@ impl Service {
             .thumbnail_properties(width, height)
             .unwrap_or((0, 0, false)); // 0, 0 because that's the original file
 
+        Ok(
             if let Ok((content_disposition, content_type, key)) =
                 self.db.search_file_metadata(mxc.clone(), width, height)
             {
@@ -125,11 +127,11 @@ impl Service {
                 let mut file = Vec::new();
                 File::open(path).await?.read_to_end(&mut file).await?;
 
-            Ok(Some(FileMeta {
+                Some(FileMeta {
                     content_disposition,
                     content_type,
                     file: file.to_vec(),
-            }))
+                })
             } else if let Ok((content_disposition, content_type, key)) =
                 self.db.search_file_metadata(mxc.clone(), 0, 0)
             {
@@ -142,13 +144,12 @@ impl Service {
                     let original_width = image.width();
                     let original_height = image.height();
                     if width > original_width || height > original_height {
-                    return Ok(Some(FileMeta {
+                        Some(FileMeta {
                             content_disposition,
                             content_type,
                             file: file.to_vec(),
-                    }));
-                }
-
+                        })
+                    } else {
                         let thumbnail = if crop {
                             image.resize_to_fill(width, height, FilterType::CatmullRom)
                         } else {
@@ -170,7 +171,8 @@ impl Service {
                                         (width, intermediate as u32)
                                     } else {
                                         (
-                                    (u64::from(width) * u64::from(::std::u32::MAX) / intermediate)
+                                            (u64::from(width) * u64::from(::std::u32::MAX)
+                                                / intermediate)
                                                 as u32,
                                             ::std::u32::MAX,
                                         )
@@ -180,7 +182,8 @@ impl Service {
                                 } else {
                                     (
                                         ::std::u32::MAX,
-                                (u64::from(height) * u64::from(::std::u32::MAX) / intermediate)
+                                        (u64::from(height) * u64::from(::std::u32::MAX)
+                                            / intermediate)
                                             as u32,
                                     )
                                 }
@@ -208,21 +211,22 @@ impl Service {
                         let mut f = File::create(path).await?;
                         f.write_all(&thumbnail_bytes).await?;
 
-                Ok(Some(FileMeta {
+                        Some(FileMeta {
                             content_disposition,
                             content_type,
                             file: thumbnail_bytes.to_vec(),
-                }))
-            } else {
-                // Couldn't parse file to generate thumbnail, send original
-                Ok(Some(FileMeta {
-                    content_disposition,
-                    content_type,
-                    file: file.to_vec(),
-                }))
+                        })
                     }
                 } else {
-            Ok(None)
+                    // Couldn't parse file to generate thumbnail, likely not an image
+                    return Err(crate::Error::BadRequest(
+                        ErrorKind::Unknown,
+                        "Unable to generate thumbnail for the requested content",
+                    ));
                 }
+            } else {
+                None
+            },
+        )
     }
 }