From e7702be5b133d1d6412c62c69c1d9a029a6b99b8 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@shopify.com>
Date: Thu, 4 Jun 2026 17:32:19 +0900
Subject: [PATCH] Avoid duplicate relative path prefix in bundle exec

When bundle exec resolves an explicit relative path like ./script and falls back to Kernel.exec, Bundler currently prepends another ./ because the resolved path is not absolute. That turns ./script into ././script, which leaks into the executed process as an unexpectedly modified argv[0].

Only prepend ./ for non-absolute paths that do not already begin with a relative path marker. This preserves the existing behavior for bare executables found in the current directory while leaving explicit relative paths unchanged.

Add a regression spec that disables exec-load so the Kernel.exec path is exercised and verifies that ./script remains ./script.

Closes https://github.com/ruby/rubygems/issues/8930
---
 bundler/lib/bundler/cli/exec.rb |  2 +-
 spec/commands/exec_spec.rb      | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/bundler/lib/bundler/cli/exec.rb b/bundler/lib/bundler/cli/exec.rb
index 2fdc4162868a..aecab5ee897b 100644
--- a/bundler/lib/bundler/cli/exec.rb
+++ b/bundler/lib/bundler/cli/exec.rb
@@ -23,7 +23,7 @@ def run
           bin_path.delete_suffix!(".bat") if Gem.win_platform?
           kernel_load(bin_path, *args)
         else
-          bin_path = "./" + bin_path unless File.absolute_path?(bin_path)
+          bin_path = "./" + bin_path unless File.absolute_path?(bin_path) || bin_path.start_with?("./", "../")
           kernel_exec(bin_path, *args)
         end
       else
diff --git a/spec/commands/exec_spec.rb b/spec/commands/exec_spec.rb
index aa35685be8ff..cc3a402629a5 100644
--- a/spec/commands/exec_spec.rb
+++ b/spec/commands/exec_spec.rb
@@ -341,6 +341,32 @@
     expect(out).to include(rubylib)
   end
 
+  it "does not duplicate a relative path prefix when exec'ing to a relative path" do
+    skip "https://github.com/ruby/rubygems/issues/3351" if Gem.win_platform?
+
+    create_file("script", "#!/usr/bin/env ruby\nputs $0")
+
+    install_gemfile <<-G
+      source "https://gem.repo1"
+    G
+
+    bundle "exec ./script", env: { "BUNDLE_DISABLE_EXEC_LOAD" => "true" }
+    expect(out).to eq("./script")
+  end
+
+  it "prepends a relative path prefix when exec'ing to a hidden file in the current directory" do
+    skip "https://github.com/ruby/rubygems/issues/3351" if Gem.win_platform?
+
+    create_file(".script", "#!/usr/bin/env ruby\nputs $0")
+
+    install_gemfile <<-G
+      source "https://gem.repo1"
+    G
+
+    bundle "exec .script", env: { "BUNDLE_DISABLE_EXEC_LOAD" => "true" }
+    expect(out).to eq("./.script")
+  end
+
   it "errors nicely when the argument doesn't exist" do
     install_gemfile <<-G
       source "https://gem.repo1"