ruby on rails コメント一覧から他のユーザーページに飛ぶ時にエラー

コメント一覧から他のユーザーページに飛ぼうとした時にこのエラーが出ました。
調べても分からなかったので教えて頂きたいです。

NoMethodError in PostsController#show
undefined method `user' for nil:NilClass Did you mean? super

該当のソースコード

posts.cotroller.rb
1class PostsController < ApplicationController
2    before_action :authenticate_user
3    before_action :ensure_correct_user, {only: [:edit, :update, :destroy]}
4
5  def index
6    @posts = Post.all.order(created_at: :desc)
7  end
8
9  def show
10    @post = Post.find_by(id: params[:id])
11    @user = @post.user ←ここがエラーになりました
12    @post = Post.find(params[:id])　
13    @comments = @post.comments
14    @comment = @comments.new
15  end
16  def new
17      @post = Post.new
18  end
19
20  def create
21    @post = Post.new(
22      content: params[:content],
23      user_id: @current_user.id
24      )
25    if @post.save
26      flash[:notice] = "投稿を作成しました"
27     redirect_to("/posts/index")
28    else
29     render("posts/new")
30    end
31  end
32
33 def edit
34  @post = Post.find_by(id: params[:id])
35 end
36
37 def update
38 @post = Post.find_by(id: params[:id])
39 @post.content = params[:content]
40 if @post.save
41   flash[:notice] = "投稿を編集しました"
42   redirect_to("/posts/index")
43 else
44   render("posts/edit")
45 end
46 end
47
48 def destroy
49   @post = Post.find_by(id: params[:id])
50   @post.destroy
51   flash[:notice] = "投稿を削除しました"
52   redirect_to("/posts/index")
53 end
54
55 def ensure_correct_user
56     @post = Post.find_by(id: params[:id])
57     if @post.user_id != @current_user.id
58         flash[:notice] = "権限がありません"
59         redirect_to("/posts/index")
60     end
61 end
62
63end

comments.controller.rb
1class CommentsController < ApplicationController
2
3   before_action :authenticate_user
4
5  def create
6    logger.debug "*"*100
7    logger.debug "[comments_controller.rb]"
8    logger.debug "*"*100
9    post = Post.find(params[:post_id])
10    @comment = post.comments.build(comment_params)
11    @comment.user_id = current_user.id
12    if @comment.save
13      logger.debug "saved"
14      flash[:success] = "コメントしました"
15      redirect_to(post)
16    else
17      logger.debug "failed"
18      flash[:success] = "コメントできませんでした"
19      redirect_to(post)
20    end
21  end
22
23  private
24
25    def comment_params
26      params.require(:comment).permit(:content)
27    end
28  logger.debug "*"*100
29end

posts/show.htmi.erb

viwe/posts/show.html.erb
1<div class="main posts-show">
2  <div class="container">
3    <div class="posts-show-item">
4      <div class="post-user-name">
5        <img src="<%= "/user_images/#{@user.image_name}" %>"> ←ここがエラー
6        <%= link_to(@user.name, "/users/#{@user.id}") %>
7      </div>
8      <p>
9        <%= @post.content %>
10      </p>
11
12      <div class="post-time">
13       <%= @post.created_at %>
14       </div>
15       <% if @post.user_id == @current_user.id %>
16       <div class="post-menus">
17        <%= link_to("編集", "/posts/#{@post.id}/edit") %>
18        <%= link_to("削除", "/posts/#{@post.id}/destroy", {method: "post"}) %>
19      </div>
20      <% end %>
21
22<div class="comment-wrapper border-top　mb-10">
23  <p class="mt-5">コメント一覧</p>
24  <% @comments.each do |c| %>
25    <div>
26      <% unless c.user.blank? %>
27        <a href="<%= (c.user_id) %>">
28          <img src="<%= "/user_images/#{c.user.image_name}" %>"></a>
29        <% end %>
30      <%= c.user.name unless c.user.blank? %>
31      <br />
32      <%= c.content %>
33    </div>
34    <br />
35  <% end %>
36  <% if user_signed_in? %>
37    <%= form_with(model: @comment, url: comments_path, method: :post, local: true) do |f| %>
38    <%= hidden_field_tag :post_id, @post.id %>
39      <%= f.text_area :content, class: "form-control", rows: 5 %>
40      <%= button_tag type: "submit", class: "btn btn-success float-right mt-1" do %>
41        <i class="far fa-comments"></i> コメントする
42      <% end %>
43    <% end %>
44  <% end %>
45</div>
46    </div>
47
48  </div>
49
50</div>

routes.rb
1Rails.application.routes.draw do
2
3  devise_for :users
4  get "login" => "users#login_form"
5
6
7  post "login" => "users#login"
8  post "logout" => "users#logout"
9
10
11  post "users/:id/update" => "users#update"
12  get "users/:id/edit" => "users#edit"
13  post "users/create" => "users#create"
14  get "singnup" => "users#new"
15  get "users/index" => "users#index"
16  get "users/:id" => "users#show", as: :user
17
18  get "posts/index" => "posts#index"
19  get "posts/new" => "posts#new"
20  get "posts/:id" => "posts#show", as: :post
21
22  resources :comments, only: [:create]
23
24
25  post "posts/create" => "posts#create"
26
27  get "posts/:id/edit" => "posts#edit"
28
29  post "posts/:id/update" => "posts#update"
30  post "posts/:id/destroy" => "posts#destroy"
31  get "/" => "home#top"
32  get "about" => "home#about"
33
34end

migrate/comments.rb
1class CreateComments < ActiveRecord::Migration[6.0]
2  def change
3    create_table :comments do |t|
4      t.string :content
5      t.references :user, null: false, foreign_key: true
6      t.references :post, null: false, foreign_key: true
7
8      t.timestamps
9    end
10  end
11end

users_controller.rb
1class UsersController < ApplicationController
2
3  before_action :authenticate_user, {only: [:index, :show, :edit, :update]}
4  before_action :forbid_login_user, {only: [:new, :create, :login_form, :login]}
5  before_action :ensure_correct_user, {only: [:edit, :update]}
6
7
8  def index
9    @users = User.all
10  end
11
12  def show
13    @user = User.find_by(id: params[:id])
14  end
15
16  def new
17    @user = User.new
18  end
19
20  def create
21    @user = User.new(
22      name: params[:name],
23      email: params[:email],
24      image_name: "fashion-985556_1920.jpg",
25      password: params[:password]
26    )
27    if @user.save
28      session[:user_id] = @user.id
29      flash[:notice] = "ユーザー登録が完了しました"
30      redirect_to("/users/#{@user.id}")
31    else
32      render("users/new")
33    end
34
35  end
36
37  def edit
38    @user = User.find_by(id: params[:id])
39  end
40
41  def update
42    @user = User.find_by(id: params[:id])
43    @user.name = params[:name]
44    @user.email = params[:email]
45
46    if params[:image]
47      @user.image_name = "#{@user.id}.jpg"
48      image = params[:image]
49      File.binwrite("public/user_images/#{@user.image_name}", image.read)
50    end
51
52    if @user.save
53      flash[:notice] = "ユーザー情報を編集しました"
54      redirect_to("/users/#{@user.id}")
55    else
56      render("users/edit")
57    end
58  end
59
60  def login_from
61  end
62
63
64  def login
65    @user = User.find_by(email: params[:email])
66    if @user && @user.valid_password?(params[:password])
67      session[:user_id] = @user.id
68      flash[:notice] = "ログインしました"
69      redirect_to("/posts/index")
70    else
71      @error_message = "メールアドレスまたはパスワードが間違っています"
72      @email = params[:email]
73      @password = params[:password]
74      render("users/login_form")
75    end
76  end
77
78  def auth_failure
79    @user = User.new
80    render("users/login_form")
81  end
82
83  def logout
84    session[:user_id] = nil
85    flash[:notice] = "ログアウトしました"
86    redirect_to("/login")
87  end
88
89  def ensure_correct_user
90    if @current_user.id != params[:id].to_i
91      flash[:notice] = "権限がありません"
92      redirect_to("/posts/index")
93    end
94  end
95
96
97end

model/comment.rb
1class Comment < ApplicationRecord
2  belongs_to :user
3  belongs_to :post
4end

model/post.rb
1class Post < ApplicationRecord
2
3  validates :content, {presence: true, length: {maximum: 140}}
4  validates :user_id, {presence: true}
5  has_many :comments
6
7  def user
8    return User.find_by(id: self.user_id)
9  end
10
11end

model/user.rb
1class User < ApplicationRecord
2  # Include default devise modules. Others available are:
3  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
4  devise :database_authenticatable, :registerable,
5         :recoverable, :rememberable, :validatable
6
7  validates :name, {presence: true}
8  validates :email, {presence: true, uniqueness: true}
9  has_many :comments
10
11  def posts
12    return Post.where(user_id: self.id)
13  end
14 end```
15