Patch for module applies with patch command but not composer

Question

I have encountered a weird issue in which a patch I rolled for Commerce does not apply with Composer; it gives no errors, but the patch is not actually applied.

  "extra": {
    "patches": {
      "drupal/commerce" : {
        "Allow order types to have no cart": "https://www.drupal.org/files/issues/commerce-direct-checkout-2.2-2810723-37.patch"
      },

However, the same patch applies correctly after downloading and using the patch command:

/web/modules/contrib/commerce$ patch -p1 < ../../../../patches/commerce-direct-checkout-2.2-2810723-37.patch
patching file modules/cart/src/Form/AddToCartForm.php
patching file modules/cart/tests/src/Functional/AddToCartFormTest.php
patching file modules/cart/tests/src/Functional/CartBrowserTestBase.php
patching file modules/product/config/schema/commerce_product.schema.yml
patching file modules/product/src/Plugin/Field/FieldFormatter/AddToCartFormatter.php
patching file modules/product/src/ProductLazyBuilders.php

What is wrong with my patch that makes it fail in Composer?

Answer 1

It turns out this is an issue with Drupal patches for composer when using an older version of Git. The problem is with composer-patches 1.6.3.

Three possible solutions for now until the bug gets fixed.

Force 1.6.2

In composer.json, specify 1.6.2:

"require": {
"composer/installers": "^1.0.20",
"cweagans/composer-patches": "1.6.2",

Force git clone with 1.6.3

In composer.json, instead of "dist", use "source":

"config": {
    "preferred-install": "source"
  },

Update git to the latest version

Answer 2

The above didn't work for me but I debugged this issue by running composer install -v for verbosity.

It will show you, for example that it is running the command

patch '-p1' --no-backup-if-mismatch -d 'web/core' < '/my/path/to/patch.patch'

I believe the -d indicates that we are running the patch from the web/core directory. When I look at this patch it looked like:

diff --git a/web/core/modules/quickedit/js/quickedit.js b/web/core/modules/quickedit/js/quickedit.js
index 4548c013a..f930746b3 100644
--- a/web/core/modules/quickedit/js/quickedit.js
+++ b/web/core/modules/quickedit/js/quickedit.js
@@ -170,7 +170,10 @@
   // code here

The a/b indicates the location of the files to patch. Since we are already in the web/core folder, it cannot find the web/core directory inside there and so fails. If we edit those two lines without that in there, it worked. ie

diff --git a/web/core/modules/quickedit/js/quickedit.js b/web/core/modules/quickedit/js/quickedit.js
index 4548c013a..f930746b3 100644
--- a/modules/quickedit/js/quickedit.js
+++ b/modules/quickedit/js/quickedit.js
@@ -170,7 +170,10 @@
// code here