fix: Assume file extensions are 32 chars max and don't contain whitespace (#5338)

Before file extensions were also limited to 32 chars, but extra chars in the beginning were just cut
off, e.g. "file.with_lots_of_characters_behind_point_and_double_ending.tar.gz" was considered to
have an extension "d_point_and_double_ending.tar.gz". Better to take only "tar.gz" then.

Also don't include whitespace-containing parts in extensions. File extensions generally don't
contain whitespaces.

Cargo.lock

@@ -1214,7 +1214,6 @@ dependencies = [
  "reqwest",
  "rusqlite",
  "rust-hsluv",
- "sanitize-filename",
  "serde",
  "serde_json",
  "sha-1",

Cargo.toml

@@ -82,7 +82,6 @@ regex = { workspace = true }
 reqwest = { version = "0.12.2", features = ["json"] }
 rusqlite = { workspace = true, features = ["sqlcipher"] }
 rust-hsluv = "0.1"
-sanitize-filename = "0.5"
 serde_json = "1"
 serde = { version = "1.0", features = ["derive"] }
 sha-1 = "0.10"

deltachat-ffi/deltachat.h

@@ -4094,7 +4094,8 @@ char*           dc_msg_get_subject            (const dc_msg_t* msg);
  *
  * Typically files are associated with images, videos, audios, documents.
  * Plain text messages do not have a file.
- * File name may be mangled. To obtain the original attachment filename use dc_msg_get_filename().
+ * The filename isn't meaningful, only the extension is preserved. To obtain the original attachment
+ * filename use dc_msg_get_filename().
  *
  * @memberof dc_msg_t
  * @param msg The message object.

node/test/test.mjs

@@ -444,7 +444,6 @@ describe('Offline Tests with unconfigured account', function () {
     context.setChatProfileImage(chatId, imagePath)
     const blobPath = context.getChat(chatId).getProfileImage()
     expect(blobPath.startsWith(blobs)).to.be.true
-    expect(blobPath.includes('image')).to.be.true
     expect(blobPath.endsWith('.jpeg')).to.be.true
 
     context.setChatProfileImage(chatId, null)

python/src/deltachat/message.py

@@ -108,7 +108,7 @@ class Message:
 
     @props.with_doc
     def filename(self):
-        """filename if there was an attachment, otherwise empty string."""
+        """file path if there was an attachment, otherwise empty string."""
         return from_dc_charpointer(lib.dc_msg_get_file(self._dc_msg))
 
     def set_file(self, path, mime_type=None):
@@ -121,7 +121,6 @@ class Message:
     @props.with_doc
     def basename(self) -> str:
         """basename of the attachment if it exists, otherwise empty string."""
-        # FIXME, it does not return basename
         return from_dc_charpointer(lib.dc_msg_get_filename(self._dc_msg))
 
     @props.with_doc

python/tests/test_1_online.py

@@ -181,13 +181,11 @@ def test_send_file_twice_unicode_filename_mangling(tmp_path, acfactory, lp):
     msg = send_and_receive_message()
     assert msg.text == "withfile"
     assert open(msg.filename).read() == "some data"
-    msg.filename.index(basename)
     assert msg.filename.endswith(ext)
 
     msg2 = send_and_receive_message()
     assert msg2.text == "withfile"
     assert open(msg2.filename).read() == "some data"
-    msg2.filename.index(basename)
     assert msg2.filename.endswith(ext)
     assert msg.filename != msg2.filename
 
@@ -214,7 +212,6 @@ def test_send_file_html_attachment(tmp_path, acfactory, lp):
     msg = ac2.get_message_by_id(ev.data2)
 
     assert open(msg.filename).read() == content
-    msg.filename.index(basename)
     assert msg.filename.endswith(ext)
 
 

python/tests/test_2_increation.py

@@ -50,7 +50,6 @@ class TestOnlineInCreation:
         src = tmp_path / "file.txt"
         src.write_text("hello there\n")
         msg = chat.send_file(str(src))
-        assert msg.filename.startswith(os.path.join(ac1.get_blobdir(), "file"))
         assert msg.filename.endswith(".txt")
 
     def test_forward_increation(self, acfactory, data, lp):

python/tests/test_3_offline.py

@@ -444,27 +444,30 @@ class TestOfflineChat:
         assert msg.filemime == "image/png"
 
     @pytest.mark.parametrize(
-        ("fn", "typein", "typeout"),
+        ("stem", "ext", "typein", "typeout"),
         [
-            ("r", None, "application/octet-stream"),
+            ("r", "", None, "application/octet-stream"),
-            ("r.txt", None, "text/plain"),
+            ("r", ".txt", None, "text/plain"),
-            ("r.txt", "text/plain", "text/plain"),
+            ("r", ".txt", "text/plain", "text/plain"),
-            ("r.txt", "image/png", "image/png"),
+            ("r", ".txt", "image/png", "image/png"),
         ],
     )
-    def test_message_file(self, chat1, data, lp, fn, typein, typeout):
+    def test_message_file(self, chat1, data, lp, stem, ext, typein, typeout):
         lp.sec("sending file")
+        fn = stem + ext
         fp = data.get_path(fn)
         msg = chat1.send_file(fp, typein)
         assert msg
         assert msg.id > 0
         assert msg.is_file()
         assert os.path.exists(msg.filename)
-        assert msg.filename.endswith(msg.basename)
+        assert msg.filename.endswith(ext)
+        assert msg.basename == fn
         assert msg.filemime == typeout
         msg2 = chat1.send_file(fp, typein)
         assert msg2 != msg
         assert msg2.filename != msg.filename
+        assert msg2.basename == fn
 
     def test_create_contact(self, acfactory):
         ac1 = acfactory.get_pseudo_configured_account()

src/blob.rs

@@ -19,7 +19,7 @@ use tokio::{fs, io};
 use tokio_stream::wrappers::ReadDirStream;
 
 use crate::config::Config;
-use crate::constants::{self, MediaQuality};
+use crate::constants::{self, MediaQuality, BLOB_CREATE_ATTEMPTS};
 use crate::context::Context;
 use crate::events::EventType;
 use crate::log::LogExt;
@@ -56,8 +56,8 @@ impl<'a> BlobObject<'a> {
         data: &[u8],
     ) -> Result<BlobObject<'a>> {
         let blobdir = context.get_blobdir();
-        let (stem, ext) = BlobObject::sanitise_name(suggested_name);
+        let ext = BlobObject::get_extension(suggested_name);
-        let (name, mut file) = BlobObject::create_new_file(context, blobdir, &stem, &ext).await?;
+        let (name, mut file) = BlobObject::create_new_file(context, blobdir, &ext).await?;
         file.write_all(data).await.context("file write failure")?;
 
         // workaround a bug in async-std
@@ -77,13 +77,11 @@ impl<'a> BlobObject<'a> {
     async fn create_new_file(
         context: &Context,
         dir: &Path,
-        stem: &str,
         ext: &str,
     ) -> Result<(String, fs::File)> {
-        const MAX_ATTEMPT: u32 = 16;
         let mut attempt = 0;
-        let mut name = format!("{stem}{ext}");
         loop {
+            let name = format!("{:016x}{}", rand::random::<u64>(), ext);
             attempt += 1;
             let path = dir.join(&name);
             match fs::OpenOptions::new()
@@ -94,12 +92,10 @@ impl<'a> BlobObject<'a> {
             {
                 Ok(file) => return Ok((name, file)),
                 Err(err) => {
-                    if attempt >= MAX_ATTEMPT {
+                    if attempt >= BLOB_CREATE_ATTEMPTS {
                         return Err(err).context("failed to create file");
                     } else if attempt == 1 && !dir.exists() {
                         fs::create_dir_all(dir).await.log_err(context).ok();
-                    } else {
-                        name = format!("{}-{}{}", stem, rand::random::<u32>(), ext);
                     }
                 }
             }
@@ -116,9 +112,9 @@ impl<'a> BlobObject<'a> {
         let mut src_file = fs::File::open(src)
             .await
             .with_context(|| format!("failed to open file {}", src.display()))?;
-        let (stem, ext) = BlobObject::sanitise_name(&src.to_string_lossy());
+        let ext = BlobObject::get_extension(&src.to_string_lossy());
         let (name, mut dst_file) =
-            BlobObject::create_new_file(context, context.get_blobdir(), &stem, &ext).await?;
+            BlobObject::create_new_file(context, context.get_blobdir(), &ext).await?;
         let name_for_err = name.clone();
         if let Err(err) = io::copy(&mut src_file, &mut dst_file).await {
             // Attempt to remove the failed file, swallow errors resulting from that.
@@ -142,10 +138,8 @@ impl<'a> BlobObject<'a> {
     ///
     /// If the source file is not a path to into the blob directory
     /// the file will be copied into the blob directory first.  If the
-    /// source file is already in the blobdir it will not be copied
+    /// source file is already in the blobdir (but not in a subdirectory)
-    /// and only be created if it is a valid blobname, that is no
+    /// it will not be copied and only be created if it is a valid blobname.
-    /// subdirectory is used and [BlobObject::sanitise_name] does not
-    /// modify the filename.
     ///
     /// Paths into the blob directory may be either defined by an absolute path
     /// or by the relative prefix `$BLOBDIR`.
@@ -162,8 +156,7 @@ impl<'a> BlobObject<'a> {
     /// Returns a [BlobObject] for an existing blob from a path.
     ///
     /// The path must designate a file directly in the blobdir and
-    /// must use a valid blob name.  That is after sanitisation the
+    /// must use a valid blob name. That means it must be valid UTF-8
-    /// name must still be the same, that means it must be valid UTF-8
     /// and not have any special characters in it.
     pub fn from_path(context: &'a Context, path: &Path) -> Result<BlobObject<'a>> {
         let rel_path = path
@@ -237,65 +230,46 @@ impl<'a> BlobObject<'a> {
         }
     }
 
-    /// Create a safe name based on a messy input string.
+    /// Get a file extension if any, including the dot, in lower case, otherwise an empty string.
-    ///
+    fn get_extension(name: &str) -> String {
-    /// The safe name will be a valid filename on Unix and Windows and
+        let mut name = name;
-    /// not contain any path separators.  The input can contain path
-    /// segments separated by either Unix or Windows path separators,
-    /// the rightmost non-empty segment will be used as name,
-    /// sanitised for special characters.
-    ///
-    /// The resulting name is returned as a tuple, the first part
-    /// being the stem or basename and the second being an extension,
-    /// including the dot.  E.g. "foo.txt" is returned as `("foo",
-    /// ".txt")` while "bar" is returned as `("bar", "")`.
-    ///
-    /// The extension part will always be lowercased.
-    fn sanitise_name(name: &str) -> (String, String) {
-        let mut name = name.to_string();
         for part in name.rsplit('/') {
             if !part.is_empty() {
-                name = part.to_string();
+                name = part;
                 break;
             }
         }
         for part in name.rsplit('\\') {
             if !part.is_empty() {
-                name = part.to_string();
+                name = part;
                 break;
             }
         }
-        let opts = sanitize_filename::Options {
-            truncate: true,
-            windows: true,
-            replacement: "",
-        };
 
-        let clean = sanitize_filename::sanitize_with_options(name, opts);
         // Let's take the tricky filename
         // "file.with_lots_of_characters_behind_point_and_double_ending.tar.gz" as an example.
-        // Split it into "file" and "with_lots_of_characters_behind_point_and_double_ending.tar.gz":
+        // Assume that the extension is 32 chars maximum.
-        let mut iter = clean.splitn(2, '.');
+        let ext: String = name
-
+            .chars()
-        let stem: String = iter.next().unwrap_or_default().chars().take(64).collect();
-        // stem == "file"
-
-        let ext_chars = iter.next().unwrap_or_default().chars();
-        let ext: String = ext_chars
             .rev()
-            .take(32)
+            .take_while(|c| !c.is_whitespace())
+            .take(33)
             .collect::<Vec<_>>()
             .iter()
             .rev()
             .collect();
-        // ext == "d_point_and_double_ending.tar.gz"
+        // ext == "nd_point_and_double_ending.tar.gz"
 
+        // Split it into "nd_point_and_double_ending" and "tar.gz":
+        let mut iter = ext.splitn(2, '.');
+        iter.next();
+
+        let ext = iter.next().unwrap_or_default();
         if ext.is_empty() {
-            (stem, "".to_string())
+            String::new()
         } else {
-            (stem, format!(".{ext}").to_lowercase())
+            format!(".{ext}").to_lowercase()
-            // Return ("file", ".d_point_and_double_ending.tar.gz")
+            // Return ".tar.gz".
-            // which is not perfect but acceptable.
         }
     }
 
@@ -743,6 +717,7 @@ fn add_white_bg(img: &mut DynamicImage) {
 #[cfg(test)]
 mod tests {
     use fs::File;
+    use regex::Regex;
 
     use super::*;
     use crate::chat::{self, create_group_chat, ProtectionStatus};
@@ -762,32 +737,43 @@ mod tests {
     async fn test_create() {
         let t = TestContext::new().await;
         let blob = BlobObject::create(&t, "foo", b"hello").await.unwrap();
-        let fname = t.get_blobdir().join("foo");
+        let re = Regex::new("^[[:xdigit:]]{16}$").unwrap();
+        assert!(re.is_match(blob.as_file_name()));
+        let fname = t.get_blobdir().join(blob.as_file_name());
         let data = fs::read(fname).await.unwrap();
         assert_eq!(data, b"hello");
-        assert_eq!(blob.as_name(), "$BLOBDIR/foo");
+        assert_eq!(
-        assert_eq!(blob.to_abs_path(), t.get_blobdir().join("foo"));
+            blob.as_name(),
+            "$BLOBDIR/".to_string() + blob.as_file_name()
+        );
+        assert_eq!(
+            blob.to_abs_path(),
+            t.get_blobdir().join(blob.as_file_name())
+        );
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_lowercase_ext() {
         let t = TestContext::new().await;
         let blob = BlobObject::create(&t, "foo.TXT", b"hello").await.unwrap();
-        assert_eq!(blob.as_name(), "$BLOBDIR/foo.txt");
+        let re = Regex::new("^\\$BLOBDIR/[[:xdigit:]]{16}.txt$").unwrap();
+        assert!(re.is_match(blob.as_name()));
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_as_file_name() {
         let t = TestContext::new().await;
         let blob = BlobObject::create(&t, "foo.txt", b"hello").await.unwrap();
-        assert_eq!(blob.as_file_name(), "foo.txt");
+        let re = Regex::new("^[[:xdigit:]]{16}.txt$").unwrap();
+        assert!(re.is_match(blob.as_file_name()));
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_as_rel_path() {
         let t = TestContext::new().await;
         let blob = BlobObject::create(&t, "foo.txt", b"hello").await.unwrap();
-        assert_eq!(blob.as_rel_path(), Path::new("foo.txt"));
+        let re = Regex::new("^[[:xdigit:]]{16}.txt$").unwrap();
+        assert!(re.is_match(blob.as_rel_path().to_str().unwrap()));
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
@@ -802,30 +788,30 @@ mod tests {
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_create_dup() {
         let t = TestContext::new().await;
-        BlobObject::create(&t, "foo.txt", b"hello").await.unwrap();
+        let re = Regex::new("^[[:xdigit:]]{16}.txt$").unwrap();
-        let foo_path = t.get_blobdir().join("foo.txt");
+
+        let blob = BlobObject::create(&t, "foo.txt", b"hello").await.unwrap();
+        assert!(re.is_match(blob.as_rel_path().to_str().unwrap()));
+        let foo_path = t.get_blobdir().join(blob.as_file_name());
         assert!(foo_path.exists());
-        BlobObject::create(&t, "foo.txt", b"world").await.unwrap();
+
-        let mut dir = fs::read_dir(t.get_blobdir()).await.unwrap();
+        let blob = BlobObject::create(&t, "foo.txt", b"world").await.unwrap();
-        while let Ok(Some(dirent)) = dir.next_entry().await {
+        assert!(re.is_match(blob.as_rel_path().to_str().unwrap()));
-            let fname = dirent.file_name();
+        let foo_path2 = t.get_blobdir().join(blob.as_file_name());
-            if fname == foo_path.file_name().unwrap() {
+        assert!(foo_path2.exists());
-                assert_eq!(fs::read(&foo_path).await.unwrap(), b"hello");
+
-            } else {
+        assert!(foo_path != foo_path2);
-                let name = fname.to_str().unwrap();
-                assert!(name.starts_with("foo"));
-                assert!(name.ends_with(".txt"));
-            }
-        }
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_double_ext_preserved() {
         let t = TestContext::new().await;
-        BlobObject::create(&t, "foo.tar.gz", b"hello")
+        let blob = BlobObject::create(&t, "foo.tar.gz", b"hello")
             .await
             .unwrap();
-        let foo_path = t.get_blobdir().join("foo.tar.gz");
+        let re = Regex::new("^[[:xdigit:]]{16}.tar.gz$").unwrap();
+        assert!(re.is_match(blob.as_file_name()));
+        let foo_path = t.get_blobdir().join(blob.as_file_name());
         assert!(foo_path.exists());
         BlobObject::create(&t, "foo.tar.gz", b"world")
             .await
@@ -838,7 +824,6 @@ mod tests {
             } else {
                 let name = fname.to_str().unwrap();
                 println!("{name}");
-                assert!(name.starts_with("foo"));
                 assert!(name.ends_with(".tar.gz"));
             }
         }
@@ -859,7 +844,8 @@ mod tests {
         let src = t.dir.path().join("src");
         fs::write(&src, b"boo").await.unwrap();
         let blob = BlobObject::create_and_copy(&t, src.as_ref()).await.unwrap();
-        assert_eq!(blob.as_name(), "$BLOBDIR/src");
+        let re = Regex::new("^\\$BLOBDIR/[[:xdigit:]]{16}$").unwrap();
+        assert!(re.is_match(blob.as_name()));
         let data = fs::read(blob.to_abs_path()).await.unwrap();
         assert_eq!(data, b"boo");
 
@@ -880,7 +866,8 @@ mod tests {
         let blob = BlobObject::new_from_path(&t, src_ext.as_ref())
             .await
             .unwrap();
-        assert_eq!(blob.as_name(), "$BLOBDIR/external");
+        let re = Regex::new("^\\$BLOBDIR/[[:xdigit:]]{16}$").unwrap();
+        assert!(re.is_match(blob.as_name()));
         let data = fs::read(blob.to_abs_path()).await.unwrap();
         assert_eq!(data, b"boo");
 
@@ -891,19 +878,6 @@ mod tests {
         let data = fs::read(blob.to_abs_path()).await.unwrap();
         assert_eq!(data, b"boo");
     }
-    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-    async fn test_create_from_name_long() {
-        let t = TestContext::new().await;
-        let src_ext = t.dir.path().join("autocrypt-setup-message-4137848473.html");
-        fs::write(&src_ext, b"boo").await.unwrap();
-        let blob = BlobObject::new_from_path(&t, src_ext.as_ref())
-            .await
-            .unwrap();
-        assert_eq!(
-            blob.as_name(),
-            "$BLOBDIR/autocrypt-setup-message-4137848473.html"
-        );
-    }
 
     #[test]
     fn test_is_blob_name() {
@@ -916,42 +890,24 @@ mod tests {
     }
 
     #[test]
-    fn test_sanitise_name() {
+    fn test_get_extension() {
-        let (stem, ext) =
+        let ext = BlobObject::get_extension("Я ЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯ.txt");
-            BlobObject::sanitise_name("Я ЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯЯ.txt");
         assert_eq!(ext, ".txt");
-        assert!(!stem.is_empty());
 
-        // the extensions are kept together as between stem and extension a number may be added -
+        let ext = BlobObject::get_extension("wot.tar.gz");
-        // and `foo.tar.gz` should become `foo-1234.tar.gz` and not `foo.tar-1234.gz`
-        let (stem, ext) = BlobObject::sanitise_name("wot.tar.gz");
-        assert_eq!(stem, "wot");
         assert_eq!(ext, ".tar.gz");
 
-        let (stem, ext) = BlobObject::sanitise_name(".foo.bar");
+        let ext = BlobObject::get_extension(".foo.bar");
-        assert_eq!(stem, "");
         assert_eq!(ext, ".foo.bar");
 
-        let (stem, ext) = BlobObject::sanitise_name("foo?.bar");
+        let ext = BlobObject::get_extension("foo?.bar");
-        assert!(stem.contains("foo"));
-        assert!(!stem.contains('?'));
         assert_eq!(ext, ".bar");
 
-        let (stem, ext) = BlobObject::sanitise_name("no-extension");
+        let ext = BlobObject::get_extension("no-extension");
-        assert_eq!(stem, "no-extension");
         assert_eq!(ext, "");
 
-        let (stem, ext) = BlobObject::sanitise_name("path/ignored\\this: is* forbidden?.c");
+        let ext = BlobObject::get_extension("path/ignored\\this: is* forbidden?.c");
         assert_eq!(ext, ".c");
-        assert!(!stem.contains("path"));
-        assert!(!stem.contains("ignored"));
-        assert!(stem.contains("this"));
-        assert!(stem.contains("forbidden"));
-        assert!(!stem.contains('/'));
-        assert!(!stem.contains('\\'));
-        assert!(!stem.contains(':'));
-        assert!(!stem.contains('*'));
-        assert!(!stem.contains('?'));
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
@@ -994,19 +950,21 @@ mod tests {
         let avatar_src = t.dir.path().join("avatar.jpg");
         let avatar_bytes = include_bytes!("../test-data/image/avatar1000x1000.jpg");
         fs::write(&avatar_src, avatar_bytes).await.unwrap();
-        let avatar_blob = t.get_blobdir().join("avatar.jpg");
-        assert!(!avatar_blob.exists());
         t.set_config(Config::Selfavatar, Some(avatar_src.to_str().unwrap()))
             .await
             .unwrap();
+        let avatar_blob = t.get_config(Config::Selfavatar).await.unwrap().unwrap();
+        let blobdir = t.get_blobdir().to_str().unwrap();
+        assert!(avatar_blob.starts_with(blobdir));
+        let re = Regex::new("[[:xdigit:]]{16}.jpg$").unwrap();
+        assert!(re.is_match(&avatar_blob));
+        let avatar_blob = Path::new(&avatar_blob);
         assert!(avatar_blob.exists());
         assert!(fs::metadata(&avatar_blob).await.unwrap().len() < avatar_bytes.len() as u64);
-        let avatar_cfg = t.get_config(Config::Selfavatar).await.unwrap();
-        assert_eq!(avatar_cfg, avatar_blob.to_str().map(|s| s.to_string()));
 
         check_image_size(avatar_src, 1000, 1000);
         check_image_size(
-            &avatar_blob,
+            avatar_blob,
             constants::BALANCED_AVATAR_SIZE,
             constants::BALANCED_AVATAR_SIZE,
         );
@@ -1016,7 +974,7 @@ mod tests {
             file.metadata().await.unwrap().len()
         }
 
-        let mut blob = BlobObject::new_from_path(&t, &avatar_blob).await.unwrap();
+        let mut blob = BlobObject::new_from_path(&t, avatar_blob).await.unwrap();
         let maybe_sticker = &mut false;
         let strict_limits = true;
         blob.recode_to_size(
@@ -1028,8 +986,8 @@ mod tests {
             strict_limits,
         )
         .unwrap();
-        assert!(file_size(&avatar_blob).await <= 3000);
+        assert!(file_size(avatar_blob).await <= 3000);
-        assert!(file_size(&avatar_blob).await > 2000);
+        assert!(file_size(avatar_blob).await > 2000);
         tokio::task::block_in_place(move || {
             let img = image::open(avatar_blob).unwrap();
             assert!(img.width() > 130);
@@ -1069,18 +1027,19 @@ mod tests {
         let avatar_src = t.dir.path().join("avatar.png");
         let avatar_bytes = include_bytes!("../test-data/image/avatar64x64.png");
         fs::write(&avatar_src, avatar_bytes).await.unwrap();
-        let avatar_blob = t.get_blobdir().join("avatar.png");
-        assert!(!avatar_blob.exists());
         t.set_config(Config::Selfavatar, Some(avatar_src.to_str().unwrap()))
             .await
             .unwrap();
-        assert!(avatar_blob.exists());
+        let avatar_blob = t.get_config(Config::Selfavatar).await.unwrap().unwrap();
+        let blobdir = t.get_blobdir().to_str().unwrap();
+        assert!(avatar_blob.starts_with(blobdir));
+        let re = Regex::new("[[:xdigit:]]{16}.png$").unwrap();
+        assert!(re.is_match(&avatar_blob));
+        assert!(Path::new(&avatar_blob).exists());
         assert_eq!(
             fs::metadata(&avatar_blob).await.unwrap().len(),
             avatar_bytes.len() as u64
         );
-        let avatar_cfg = t.get_config(Config::Selfavatar).await.unwrap();
-        assert_eq!(avatar_cfg, avatar_blob.to_str().map(|s| s.to_string()));
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]

src/chat.rs

@@ -4520,6 +4520,7 @@ mod tests {
     use crate::message::delete_msgs;
     use crate::receive_imf::receive_imf;
     use crate::test_utils::{sync, TestContext, TestContextManager};
+    use regex::Regex;
     use strum::IntoEnumIterator;
     use tokio::fs;
 
@@ -7078,9 +7079,11 @@ mod tests {
 
         // the file bob receives should not contain BIDI-control characters
         assert_eq!(
-            Some("$BLOBDIR/harmless_file.txt.exe"),
+            msg.param.get(Param::Filename).unwrap(),
-            msg.param.get(Param::File),
+            "harmless_file.txt.exe"
         );
+        let re = Regex::new("^\\$BLOBDIR/[[:xdigit:]]{16}.txt.exe$").unwrap();
+        assert!(re.is_match(msg.param.get(Param::File).unwrap()));
         Ok(())
     }
 

src/constants.rs

@@ -211,6 +211,9 @@ pub(crate) const DC_FOLDERS_CONFIGURED_KEY: &str = "folders_configured";
 // this value can be increased if the folder configuration is changed and must be redone on next program start
 pub(crate) const DC_FOLDERS_CONFIGURED_VERSION: i32 = 4;
 
+// Maximum attemps to create a blob file.
+pub(crate) const BLOB_CREATE_ATTEMPTS: u32 = 2;
+
 // If more recipients are needed in SMTP's `RCPT TO:` header, the recipient list is split into
 // chunks. This does not affect MIME's `To:` header. Can be overwritten by setting
 // `max_smtp_rcpt_to` in the provider db.

src/debug_logging.rs

@@ -9,7 +9,6 @@ use crate::tools::time;
 use crate::webxdc::StatusUpdateItem;
 use async_channel::{self as channel, Receiver, Sender};
 use serde_json::json;
-use std::path::PathBuf;
 use tokio::task;
 
 #[derive(Debug)]
@@ -98,7 +97,7 @@ pub async fn maybe_set_logging_xdc(
         context,
         msg.get_viewtype(),
         chat_id,
-        msg.param.get_path(Param::File, context).unwrap_or_default(),
+        msg.param.get(Param::Filename),
         msg.get_id(),
     )
     .await?;
@@ -111,18 +110,16 @@ pub async fn maybe_set_logging_xdc_inner(
     context: &Context,
     viewtype: Viewtype,
     chat_id: ChatId,
-    file: Option<PathBuf>,
+    file_name: Option<&str>,
     msg_id: MsgId,
 ) -> anyhow::Result<()> {
     if viewtype == Viewtype::Webxdc {
-        if let Some(file) = file {
+        if let Some(file_name) = file_name {
-            if let Some(file_name) = file.file_name().and_then(|name| name.to_str()) {
+            if file_name.starts_with("debug_logging")
-                if file_name.starts_with("debug_logging")
+                && file_name.ends_with(".xdc")
-                    && file_name.ends_with(".xdc")
+                && chat_id.is_self_talk(context).await?
-                    && chat_id.is_self_talk(context).await?
+            {
-                {
+                set_debug_logging_xdc(context, Some(msg_id)).await?;
-                    set_debug_logging_xdc(context, Some(msg_id)).await?;
-                }
             }
         }
     }

src/imex/transfer.rs

@@ -651,8 +651,9 @@ mod tests {
         };
         let msg = Message::load_from_db(&ctx1, *msgid).await.unwrap();
 
+        assert_eq!(&msg.get_filename().unwrap(), "hello.txt");
         let path = msg.get_file(&ctx1).unwrap();
-        assert_eq!(path.with_file_name("hello.txt"), path);
+        assert_eq!(path.with_extension("txt"), path);
         let text = fs::read_to_string(&path).await.unwrap();
         assert_eq!(text, "i am attachment");
 

src/message.rs

@@ -304,7 +304,12 @@ WHERE id=?;
 
         if let Some(path) = msg.get_file(context) {
             let bytes = get_filebytes(context, &path).await?;
-            ret += &format!("\nFile: {}, {} bytes\n", path.display(), bytes);
+            ret += &format!(
+                "\nFile: {}, name: {}, {} bytes\n",
+                path.display(),
+                msg.get_filename().unwrap_or_default(),
+                bytes
+            );
         }
 
         if msg.viewtype != Viewtype::Text {
@@ -601,7 +606,8 @@ impl Message {
         None
     }
 
-    /// Returns the full path to the file associated with a message.
+    /// Returns the full path to the file associated with a message. The filename isn't meaningful,
+    /// only the extension is preserved.
     pub fn get_file(&self, context: &Context) -> Option<PathBuf> {
         self.param.get_path(Param::File, context).unwrap_or(None)
     }
@@ -754,8 +760,6 @@ impl Message {
     }
 
     /// Returns original filename (as shown in chat).
-    ///
-    /// To get the full path, use [`Self::get_file()`].
     pub fn get_filename(&self) -> Option<String> {
         if let Some(name) = self.param.get(Param::Filename) {
             return Some(name.to_string());

src/mimeparser.rs

@@ -2254,6 +2254,7 @@ mod tests {
     #![allow(clippy::indexing_slicing)]
 
     use mailparse::ParsedMail;
+    use regex::Regex;
 
     use super::*;
     use crate::{
@@ -3454,7 +3455,7 @@ On 2020-10-25, Bob wrote:
         assert_eq!(msg.chat_blocked, Blocked::Request);
         assert_eq!(msg.state, MessageState::InFresh);
         assert_eq!(msg.get_filebytes(&t).await.unwrap().unwrap(), 2115);
-        assert!(msg.get_file(&t).is_some());
+        assert_eq!(msg.get_file(&t).unwrap().extension().unwrap(), "png");
         assert_eq!(msg.get_filename().unwrap(), "avatar64x64.png");
         assert_eq!(msg.get_width(), 64);
         assert_eq!(msg.get_height(), 64);
@@ -3800,10 +3801,8 @@ Message.
             mime_message.parts[0].msg,
             "this is a classic email – I attached the .EML file".to_string()
         );
-        assert_eq!(
+        let re = Regex::new("^\\$BLOBDIR/[[:xdigit:]]{16}.eml$").unwrap();
-            mime_message.parts[0].param.get(Param::File),
+        assert!(re.is_match(mime_message.parts[0].param.get(Param::File).unwrap()));
-            Some("$BLOBDIR/.eml")
-        );
 
         assert_eq!(mime_message.parts[0].org_filename, Some(".eml".to_string()));
 

src/param.rs

@@ -547,8 +547,6 @@ mod tests {
         assert!(p.get_blob(Param::File, &t, false).await.is_err());
 
         fs::write(fname, b"boo").await.unwrap();
-        let blob = p.get_blob(Param::File, &t, true).await.unwrap().unwrap();
-        assert!(blob.as_file_name().starts_with("foo"));
 
         // Blob in blobdir, expect blob.
         let bar_path = t.get_blobdir().join("bar");

src/receive_imf.rs

@@ -1577,9 +1577,7 @@ RETURNING id
             context,
             part.typ,
             chat_id,
-            part.param
+            part.param.get(Param::Filename),
-                .get_path(Param::File, context)
-                .unwrap_or_default(),
             *msg_id,
         )
         .await?;

src/receive_imf/tests.rs

@@ -1,5 +1,6 @@
 use std::time::Duration;
 
+use regex::Regex;
 use tokio::fs;
 
 use super::*;
@@ -1593,7 +1594,6 @@ async fn test_pdf_filename_simple() {
     assert_eq!(msg.viewtype, Viewtype::File);
     assert_eq!(msg.text, "mail body");
     let file_path = msg.param.get(Param::File).unwrap();
-    assert!(file_path.starts_with("$BLOBDIR/simple"));
     assert!(file_path.ends_with(".pdf"));
 }
 
@@ -1609,7 +1609,6 @@ async fn test_pdf_filename_continuation() {
     assert_eq!(msg.viewtype, Viewtype::File);
     assert_eq!(msg.text, "mail body");
     let file_path = msg.param.get(Param::File).unwrap();
-    assert!(file_path.starts_with("$BLOBDIR/test pdf äöüß"));
     assert!(file_path.ends_with(".pdf"));
 }
 
@@ -2962,20 +2961,27 @@ Reply from different address
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn test_long_and_duplicated_filenames() -> Result<()> {
+async fn test_weird_and_duplicated_filenames() -> Result<()> {
     let mut tcm = TestContextManager::new();
     let alice = tcm.alice().await;
     let bob = tcm.bob().await;
 
-    for filename_sent in &[
+    for (filename_sent, expected_ext) in &[
-        "foo.bar very long file name test baz.tar.gz",
+        ("foo.bar very long file name test baz.tar.gz", "tar.gz"),
-        "foobarabababababababbababababverylongfilenametestbaz.tar.gz",
+        (
-        "fooo...tar.gz",
+            "foo.barabababababababbababababverylongfilenametestbaz.tar.gz",
-        "foo. .tar.gz",
+            "tar.gz",
-        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.tar.gz",
+        ),
-        "a.tar.gz",
+        ("fooo...tar.gz", "..tar.gz"),
-        "a.tar.gz",
+        ("foo. .tar.gz", "tar.gz"),
-        "a.a..a.a.a.a.tar.gz",
+        (
+            "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.tar.gz",
+            "tar.gz",
+        ),
+        ("a.tar.gz", "tar.gz"),
+        ("a.tar.gz", "tar.gz"),
+        ("a.a..a.a.a.a.tar.gz", "a..a.a.a.a.tar.gz"),
+        ("a. tar.tar.gz", "tar.gz"),
     ] {
         let attachment = alice.blobdir.join(filename_sent);
         let content = format!("File content of {filename_sent}");
@@ -2989,23 +2995,33 @@ async fn test_long_and_duplicated_filenames() -> Result<()> {
 
         let msg_bob = bob.recv_msg(&sent).await;
 
-        async fn check_message(msg: &Message, t: &TestContext, filename: &str, content: &str) {
+        async fn check_message(
+            msg: &Message,
+            t: &TestContext,
+            filename: &str,
+            expected_ext: &str,
+            content: &str,
+        ) {
             assert_eq!(msg.get_viewtype(), Viewtype::File);
             let resulting_filename = msg.get_filename().unwrap();
             assert_eq!(resulting_filename, filename);
             let path = msg.get_file(t).unwrap();
+            if !msg.get_state().is_outgoing() {
+                let re =
+                    Regex::new(&("^[[:xdigit:]]{16}.".to_string() + expected_ext + "$")).unwrap();
+                assert!(
+                    re.is_match(path.file_name().unwrap().to_str().unwrap()),
+                    "invalid path {path:?}"
+                );
+            }
             let path2 = path.with_file_name("saved.txt");
             msg.save_file(t, &path2).await.unwrap();
-            assert!(
-                path.to_str().unwrap().ends_with(".tar.gz"),
-                "path {path:?} doesn't end with .tar.gz"
-            );
             assert_eq!(fs::read_to_string(&path).await.unwrap(), content);
             assert_eq!(fs::read_to_string(&path2).await.unwrap(), content);
             fs::remove_file(path2).await.unwrap();
         }
-        check_message(&msg_alice, &alice, filename_sent, &content).await;
+        check_message(&msg_alice, &alice, filename_sent, expected_ext, &content).await;
-        check_message(&msg_bob, &bob, filename_sent, &content).await;
+        check_message(&msg_bob, &bob, filename_sent, expected_ext, &content).await;
     }
 
     Ok(())