From 226908b5baa1dc888d2cf9fe5e44f16b0c8723a6 Mon Sep 17 00:00:00 2001
From: Anton Maminov <anton.linux@gmail.com>
Date: Tue, 17 Aug 2021 01:03:21 +0300
Subject: [PATCH 1/2] follow redirects

---
 spec/redirect_spec.cr       | 17 +++++++++++++++++
 src/mechanize/http/agent.cr | 17 +++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 spec/redirect_spec.cr

diff --git a/spec/redirect_spec.cr b/spec/redirect_spec.cr
new file mode 100644
index 0000000..89c56b9
--- /dev/null
+++ b/spec/redirect_spec.cr
@@ -0,0 +1,17 @@
+require "./spec_helper"
+
+WebMock.stub(:get, "http://example.com/redirect").to_return(body: "success")
+
+WebMock.stub(:post, "http://example.com/post")
+  .with(body: "email=foobar", headers: {"Content-Type" => "application/x-www-form-urlencoded"})
+  .to_return(status: 302, body: "redirect", headers: {"Location" => "http://example.com/redirect"})
+
+describe "Mechanize redirect test" do
+  it "redirect" do
+    agent = Mechanize.new
+    query = {"email" => "foobar"}
+    page = agent.post("http://example.com/post", query: query)
+    page.body.should eq("success")
+    page.code.should eq(200)
+  end
+end
diff --git a/src/mechanize/http/agent.cr b/src/mechanize/http/agent.cr
index 1bb7874..4b57f2a 100644
--- a/src/mechanize/http/agent.cr
+++ b/src/mechanize/http/agent.cr
@@ -30,9 +30,26 @@ module MechanizeCr
         page = response_parse(response, body, uri)
         # save cookies
         save_response_cookies(response, uri, page)
+
+        if response && response.status.redirection?
+          return follow_redirect(response, headers)
+        end
+
         page
       end
 
+      private def follow_redirect(response, headers)
+        redirect_url = response.headers["location"]
+        uri = URI.parse(redirect_url)
+
+        # Make sure we are not copying over the POST headers from the original request
+        headers.delete("Content-MD5")
+        headers.delete("Content-Type")
+        headers.delete("Content-Length")
+
+        @context.not_nil!.get(uri)
+      end
+
       def http_request(uri, method, params)
         case uri.scheme.not_nil!.downcase
         when "http", "https" then

From 810f9ae430d3790b84dd8cbcc9aa3b4ee1be32f6 Mon Sep 17 00:00:00 2001
From: Kanezoh <asfaltmanta114@gmail.com>
Date: Tue, 17 Aug 2021 14:30:08 +0900
Subject: [PATCH 2/2] complete url if location header is relative path

---
 spec/redirect_spec.cr       | 12 ++++++++++++
 src/mechanize/http/agent.cr |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/spec/redirect_spec.cr b/spec/redirect_spec.cr
index 89c56b9..27f3e32 100644
--- a/spec/redirect_spec.cr
+++ b/spec/redirect_spec.cr
@@ -6,6 +6,10 @@ WebMock.stub(:post, "http://example.com/post")
   .with(body: "email=foobar", headers: {"Content-Type" => "application/x-www-form-urlencoded"})
   .to_return(status: 302, body: "redirect", headers: {"Location" => "http://example.com/redirect"})
 
+WebMock.stub(:post, "http://example.com/post2")
+  .with(body: "email=foobar", headers: {"Content-Type" => "application/x-www-form-urlencoded"})
+  .to_return(status: 302, body: "redirect", headers: {"Location" => "/redirect"})
+
 describe "Mechanize redirect test" do
   it "redirect" do
     agent = Mechanize.new
@@ -14,4 +18,12 @@ describe "Mechanize redirect test" do
     page.body.should eq("success")
     page.code.should eq(200)
   end
+
+  it "redirect with relative path" do
+    agent = Mechanize.new
+    query = {"email" => "foobar"}
+    page = agent.post("http://example.com/post2", query: query)
+    page.body.should eq("success")
+    page.code.should eq(200)
+  end
 end
diff --git a/src/mechanize/http/agent.cr b/src/mechanize/http/agent.cr
index 4b57f2a..e1e80b3 100644
--- a/src/mechanize/http/agent.cr
+++ b/src/mechanize/http/agent.cr
@@ -32,15 +32,15 @@ module MechanizeCr
         save_response_cookies(response, uri, page)
 
         if response && response.status.redirection?
-          return follow_redirect(response, headers)
+          return follow_redirect(response, headers, page)
         end
 
         page
       end
 
-      private def follow_redirect(response, headers)
+      private def follow_redirect(response, headers, referer)
         redirect_url = response.headers["location"]
-        uri = URI.parse(redirect_url)
+        uri = resolve_url(redirect_url, referer)
 
         # Make sure we are not copying over the POST headers from the original request
         headers.delete("Content-MD5")