git-lfs: ignore filtered files in .gitattributes during snapshot

CHANGELOG.md

@@ -29,6 +29,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 * [Diff colors](docs/config.md#diff-colors-and-styles) can now be configured
   differently for each format.
 
+* Added `git.ignore-filters` setting to specify what filtered files in
+  `.gitattributes` are ignored by `jj`. Defaults to `["lfs"]`.
+
 ### Fixed bugs
 
 * `.gitignore` with UTF-8 BOM can now be parsed correctly.

Cargo.toml

@@ -57,6 +57,7 @@ gix = { version = "0.80.0", default-features = false, features = [
     "max-performance-safe",
     "zlib-rs",
 ] }
+gix-attributes = "0.31.0"
 globset = "0.4.18"
 hashbrown = { version = "0.16.1", default-features = false, features = ["inline-more"] }
 ignore = "0.4.25"
@@ -112,7 +113,7 @@ test-case = "3.3.1"
 textwrap = "0.16.2"
 thiserror = "2.0.17"
 timeago = { version = "0.6.0", default-features = false }
-tokio = { version = "1.50.0", features = ["io-util"] }
+tokio = { version = "1.50.0", features = ["io-util", "sync"] }
 toml = "1.0.6"
 toml_edit = { version = "0.25.4", features = ["serde"] }
 tracing = "0.1.44"

cli/src/command_error.rs

@@ -34,6 +34,7 @@ use jj_lib::fileset::FilePatternParseError;
 use jj_lib::fileset::FilesetParseError;
 use jj_lib::fileset::FilesetParseErrorKind;
 use jj_lib::fix::FixError;
+use jj_lib::gitattributes::GitAttributesError;
 use jj_lib::gitignore::GitIgnoreError;
 use jj_lib::index::IndexError;
 use jj_lib::op_heads_store::OpHeadResolutionError;
@@ -725,6 +726,12 @@ impl From<GitIgnoreError> for CommandError {
     }
 }
 
+impl From<GitAttributesError> for CommandError {
+    fn from(err: GitAttributesError) -> Self {
+        user_error_with_message("Failed to process .gitattributes.", err)
+    }
+}
+
 impl From<ParseBulkEditMessageError> for CommandError {
     fn from(err: ParseBulkEditMessageError) -> Self {
         user_error(err)

cli/src/config-schema.json

@@ -517,6 +517,14 @@
                     "type": "boolean",
                     "description": "Whether to colocate the working copy with the git repository",
                     "default": true
+                },
+                "ignore-filters": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    },
+                    "description": "Names of `.gitattributes` filter attributes whose matching files should be excluded from snapshots",
+                    "default": ["lfs"]
                 }
             }
         },

cli/src/config/misc.toml

@@ -25,6 +25,7 @@ disabled-branches = []
 
 [git]
 colocate = true
+ignore-filters = ["lfs"]
 private-commits = "none()"
 push-new-bookmarks = false
 sign-on-push = false

cli/src/merge_tools/diff_working_copies.rs

@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::collections::HashSet;
 use std::fs::File;
 use std::io;
 use std::io::Write as _;
@@ -156,6 +157,7 @@ pub(crate) async fn check_out_trees(
             eol_conversion_mode: EolConversionMode::None,
             exec_change_setting: ExecChangeSetting::Auto,
             fsmonitor_settings: FsmonitorSettings::None,
+            ignore_filters: HashSet::new(),
         };
         let mut state = TreeState::init(store.clone(), wc_path, state_dir, &tree_state_settings)?;
         state.set_sparse_patterns(changed_files.clone())?;

lib/Cargo.toml

@@ -41,6 +41,7 @@ either = { workspace = true }
 etcetera = { workspace = true }
 futures = { workspace = true }
 gix = { workspace = true, optional = true }
+gix-attributes = { workspace = true }
 globset = { workspace = true }
 hashbrown = { workspace = true }
 ignore = { workspace = true }

lib/src/git.rs

@@ -40,6 +40,7 @@ use crate::backend::CommitId;
 use crate::backend::TreeValue;
 use crate::commit::Commit;
 use crate::config::ConfigGetError;
+use crate::config::ConfigGetResultExt as _;
 use crate::file_util::IoResultExt as _;
 use crate::file_util::PathError;
 use crate::git_backend::GitBackend;
@@ -99,6 +100,7 @@ pub struct GitSettings {
     pub abandon_unreachable_commits: bool,
     pub executable_path: PathBuf,
     pub write_change_id_header: bool,
+    pub ignore_filters: Vec<String>,
 }
 
 impl GitSettings {
@@ -108,6 +110,10 @@ impl GitSettings {
             abandon_unreachable_commits: settings.get_bool("git.abandon-unreachable-commits")?,
             executable_path: settings.get("git.executable-path")?,
             write_change_id_header: settings.get("git.write-change-id-header")?,
+            ignore_filters: settings
+                .get("git.ignore-filters")
+                .optional()?
+                .unwrap_or_else(|| vec!["lfs".to_string()]),
         })
     }