git: Introduce depth argument for fetching

cli/src/commands/git/clone.rs

@@ -219,6 +219,7 @@ fn do_git_clone(
         git::fetch(
             fetch_tx.repo_mut(),
             &git_repo,
+            None,
             remote_name,
             &[StringPattern::everything()],
             cb,

cli/src/commands/git/fetch.rs

@@ -73,6 +73,7 @@ pub fn cmd_git_fetch(
             git::fetch(
                 tx.repo_mut(),
                 &git_repo,
+                None,
                 remote,
                 &args.branch,
                 cb,

lib/src/git.rs

@@ -21,6 +21,7 @@ use std::collections::HashSet;
 use std::default::Default;
 use std::fmt;
 use std::io::Read;
+use std::num::NonZeroU32;
 use std::path::PathBuf;
 use std::str;
 
@@ -1240,6 +1241,7 @@ pub struct GitFetchStats {
 pub fn fetch(
     mut_repo: &mut MutableRepo,
     git_repo: &git2::Repository,
+    depth: Option<NonZeroU32>,
     remote_name: &str,
     branch_names: &[StringPattern],
     callbacks: RemoteCallbacks<'_>,
@@ -1260,6 +1262,9 @@ pub fn fetch(
     fetch_options.proxy_options(proxy_options);
     let callbacks = callbacks.into_git();
     fetch_options.remote_callbacks(callbacks);
+    if let Some(depth) = depth.and_then(|depth| depth.get().try_into().ok()) {
+        fetch_options.depth(depth);
+    }
     // At this point, we are only updating Git's remote tracking branches, not the
     // local branches.
     let refspecs: Vec<_> = branch_names

lib/tests/test_git.rs

@@ -2266,6 +2266,7 @@ fn test_fetch_empty_repo() {
     let stats = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2292,6 +2293,7 @@ fn test_fetch_initial_commit() {
     let stats = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2342,6 +2344,7 @@ fn test_fetch_success() {
     git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2365,6 +2368,7 @@ fn test_fetch_success() {
     let stats = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2422,6 +2426,7 @@ fn test_fetch_prune_deleted_ref() {
     git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2445,6 +2450,7 @@ fn test_fetch_prune_deleted_ref() {
     let stats = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2472,6 +2478,7 @@ fn test_fetch_no_default_branch() {
     git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2495,6 +2502,7 @@ fn test_fetch_no_default_branch() {
     let stats = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
@@ -2516,6 +2524,7 @@ fn test_fetch_empty_refspecs() {
     git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "origin",
         &[],
         git::RemoteCallbacks::default(),
@@ -2542,6 +2551,7 @@ fn test_fetch_no_such_remote() {
     let result = git::fetch(
         tx.repo_mut(),
         &test_data.git_repo,
+        None,
         "invalid-remote",
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),