Use -c to specify the default branch name.

Partial revert of 44ffa2f.

src/summarizer/tests.rs

@@ -89,6 +89,7 @@ fn collect_dir_data() {
             let mut git = Command::new("git");
             git.current_dir(root.path())
                 .stdout(Stdio::null())
+                .args(["-c", "init.defaultBranch=x"])
                 .args(["-c", "user.name=ab"])
                 .args(["-c", "user.email=a@b"]);
 
@@ -100,7 +101,7 @@ fn collect_dir_data() {
         };
     }
 
-    run_git!("init -b x");
+    run_git!("init");
     run_git!("add .");
     run_git!("commit -m x");
 

src/tests/ui/collector.sh

@@ -21,7 +21,7 @@ fallocate -l 140K ddd/dd/file2
 seq 20 > ccccc/file3
 seq 30 > file4
 
-git init -b x 1>&2
+git init 1>&2
 git add .
 git -c user.email=x -c user.name=x commit -m X 1>&2
 

src/tests/ui/styles.sh

@@ -61,7 +61,7 @@ touch N{1..20}
 mkdir dir0 dir1
 fallocate -l100 dir0/x
 
-git init -b x 1>&2
+git init 1>&2
 seq 10 > X
 git add X
 git -c user.email=x -c user.name=x commit -m X 1>&2