From 9ca4d4aeccf50e6c036e5536ef070a09c1776817 Mon Sep 17 00:00:00 2001
From: Stephen Gallagher <sgallagh@redhat.com>
Date: Fri, 6 Dec 2019 16:40:25 -0500
Subject: [PATCH 3/3] build: auto-load ICU data from
 --with-icu-default-data-dir

When compiled with `--with-intl=small` and
`--with-icu-default-data-dir=PATH`, Node.js will use PATH as a
fallback location for the ICU data.

We will first perform an access check using fopen(PATH, 'r') to
ensure that the file is readable. If it is, we'll set the
icu_data_directory and proceed. There's a slight overhead for the
fopen() check, but it should be barely measurable.

This will be useful for Linux distribution packagers who want to
be able to ship a minimal node binary in a container image but
also be able to add on the full i18n support where needed. With
this patch, it becomes possible to ship the interpreter as
/usr/bin/node in one package for the distribution and to ship the
data files in another package (without a strict dependency
between the two). This means that users of the distribution will
not need to explicitly direct Node.js to locate the ICU data. It
also means that in environments where full internationalization is
not required, they do not need to carry the extra content (with
the associated storage costs).

Refs: https://github.com/nodejs/node/issues/3460

Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>
---
 configure.py |  9 +++++++++
 node.gypi    |  7 +++++++
 src/node.cc  | 20 ++++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/configure.py b/configure.py
index 48389fbdcb57cbf8d9c11d4921c65f34a1937cc7..063e8748b954a7fed4fe084399e61371c061edab 100755
--- a/configure.py
+++ b/configure.py
@@ -433,6 +433,14 @@ intl_optgroup.add_option('--with-icu-source',
         'the icu4c source archive. '
         'v%d.x or later recommended.' % icu_versions['minimum_icu'])

+intl_optgroup.add_option('--with-icu-default-data-dir',
+    action='store',
+    dest='with_icu_default_data_dir',
+    help='Path to the icuXXdt{lb}.dat file. If unspecified, ICU data will '
+         'only be read if the NODE_ICU_DATA environment variable or the '
+         '--icu-data-dir runtime argument is used. This option has effect '
+         'only when Node.js is built with --with-intl=small-icu.')
+
 parser.add_option('--with-ltcg',
     action='store_true',
     dest='with_ltcg',
@@ -1360,6 +1368,7 @@ def configure_intl(o):
     locs.add('root')  # must have root
     o['variables']['icu_locales'] = string.join(locs,',')
     # We will check a bit later if we can use the canned deps/icu-small
+    o['variables']['icu_default_data'] = options.with_icu_default_data_dir or ''
   elif with_intl == 'full-icu':
     # full ICU
     o['variables']['v8_enable_i18n_support'] = 1
diff --git a/node.gypi b/node.gypi
index 466a1746811cfac1a8ce4ef604ef1152c6229ff1..65b97d6466a14f4343a948a5fc36f8a2580badfb 100644
--- a/node.gypi
+++ b/node.gypi
@@ -113,6 +113,13 @@
       'conditions': [
         [ 'icu_small=="true"', {
           'defines': [ 'NODE_HAVE_SMALL_ICU=1' ],
+          'conditions': [
+            [ 'icu_default_data!=""', {
+              'defines': [
+                'NODE_ICU_DEFAULT_DATA_DIR="<(icu_default_data)"',
+              ],
+            }],
+          ],
       }]],
     }],
     [ 'node_use_bundled_v8=="true" and \
diff --git a/src/node.cc b/src/node.cc
index 7c0118758dfd9449283b900209b2ba8df7ddd129..c9840e3e367ca47176a17a7940a1e08eb1f56f78 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -92,6 +92,7 @@

 #if defined(NODE_HAVE_I18N_SUPPORT)
 #include <unicode/uvernum.h>
+#include <unicode/utypes.h>
 #endif

 #if defined(LEAK_SANITIZER)
@@ -2643,6 +2644,25 @@ void Init(std::vector<std::string>* argv,
   // If the parameter isn't given, use the env variable.
   if (per_process_opts->icu_data_dir.empty())
     SafeGetenv("NODE_ICU_DATA", &per_process_opts->icu_data_dir);
+
+#ifdef NODE_ICU_DEFAULT_DATA_DIR
+  // If neither the CLI option nor the environment variable was specified,
+  // fall back to the configured default
+  if (per_process_opts->icu_data_dir.empty()) {
+    // Check whether the NODE_ICU_DEFAULT_DATA_DIR contains the right data
+    // file and can be read.
+    static const char full_path[] =
+        NODE_ICU_DEFAULT_DATA_DIR "/" U_ICUDATA_NAME ".dat";
+
+    FILE* f = fopen(full_path, "rb");
+
+    if (f != nullptr) {
+      fclose(f);
+      per_process_opts->icu_data_dir = NODE_ICU_DEFAULT_DATA_DIR;
+    }
+  }
+#endif  // NODE_ICU_DEFAULT_DATA_DIR
+
   // Initialize ICU.
   // If icu_data_dir is empty here, it will load the 'minimal' data.
   if (!i18n::InitializeICUDirectory(per_process_opts->icu_data_dir)) {
--
2.24.1