add bisect information and update man page

XD.1

@@ -26,6 +26,7 @@ tab(;) allbox;
 c;l.
  :;default
  \;;in a git repo
+ =;in a git repo during a bisect
  8;in a git repo with stashed changes
  X;in a git repo during a merge
  O;in a git repo during a rebase
@@ -56,8 +57,8 @@ c;l.
 returns the number that was passed in to allow the user to re-run the program
 and get the same results. If there's an internal error
 .Nm
-returns 1. If you wish to find out more infomation about the error enable ERR
-in the config.mk.
+returns 1. If you wish to find out more infomation about the error pass in
+-Derr at build time.
 .Sh OPTIONS
 .Ss -v
 Print version information to stdout and exit.

src/Git.zig

@@ -10,7 +10,7 @@ const std = @import("std");
 const util = @import("util.zig");
 
 repo: ?*c.git_repository,
-git_path: []const u8,
+git_path: [:0]const u8,
 repo_path: []const u8,
 allocator: std.mem.Allocator,
 repo_state: c_int,
@@ -43,7 +43,7 @@ pub fn init(allocator: std.mem.Allocator) !?*Git {
         .allocator = allocator,
         .repo_state = undefined,
         .repo_path = undefined,
-        .cache = .init(self.allocator, self.git_path),
+        .cache = .init(self.allocator, std.mem.span(self.git_path.ptr)),
     };
 
     if (c.git_repository_open(&self.repo, repo_root.?.ptr) != 0) {
@@ -114,6 +114,20 @@ pub fn inRebase(self: *Git) bool {
     };
 }
 
+pub fn inBisect(self: *Git) bool {
+    const s = perf.s();
+    defer perf.e(s, @src());
+
+    const path = std.fs.path.join(self.allocator, &[_][]const u8{
+        std.mem.span(self.git_path.ptr),
+        "BISECT_LOG",
+    }) catch return false;
+    defer self.allocator.free(path);
+
+    std.fs.cwd().access(path, .{ .mode = .read_only }) catch return false;
+    return true;
+}
+
 pub fn hasStaged(self: *Git) bool {
     const s = perf.s();
     defer perf.e(s, @src());
@@ -238,7 +252,7 @@ pub fn headIsDetached(self: *Git) bool {
     return c.git_repository_head_detached(self.repo) == 1;
 }
 
-fn findRepoRoot(allocator: std.mem.Allocator) !?[]u8 {
+fn findRepoRoot(allocator: std.mem.Allocator) !?[:0]u8 {
     const s = perf.s();
     defer perf.e(s, @src());
 
@@ -260,20 +274,18 @@ fn findRepoRoot(allocator: std.mem.Allocator) !?[]u8 {
         };
 
         return switch (stat.kind) {
-            .directory => try allocator.dupe(u8, try cur_path.realpathZ(
+            .directory => try allocator.dupeZ(u8, try cur_path.realpath(
                 ".git",
                 &buf,
             )),
             .file => {
                 @branchHint(.cold);
-                const f = try cur_path.openFile(".git", .{ .mode = .read_only });
-                const file_reader = f.reader(&buf);
-                var reader = file_reader.interface;
-                const read = try reader.readSliceShort(&buf);
                 const prefix = "gitdir: ";
-                if (std.mem.startsWith(u8, &buf, prefix)) {
-                    buf[read - 1] = 0; // remove the newline
-                    return try allocator.dupe(u8, buf[prefix.len..]);
+                var file_buf: [std.fs.max_path_bytes + prefix.len]u8 = undefined;
+                const read = try cur_path.readFile(".git", &file_buf);
+
+                if (read.len > 0 and std.mem.eql(u8, file_buf[0..prefix.len], prefix)) {
+                    return try allocator.dupeZ(u8, read[prefix.len..read.len - 1]);
                 }
                 return null;
             },

src/main.zig

@@ -59,7 +59,12 @@ pub fn main() u8 {
     var git = if (config.git) try @import("Git.zig").init(allocator) orelse null;
     defer if (config.git and git != null) git.?.deinit();
     if (config.git and git != null) {
-        if (git.?.hasStashes()) {
+        if (git.?.inBisect()) {
+            face[@intFromEnum(FaceParts.eyes)] = .{
+                .symbol = '=',
+                .explanation = "The current git repo is bisecting.",
+            };
+        } else if (git.?.hasStashes()) {
             face[@intFromEnum(FaceParts.eyes)] = .{
                 .symbol = '8',
                 .explanation = "The current git repo has stashed changes.",