From 3042e1a62f446487f6321aebb1fbebaadd403028 Mon Sep 17 00:00:00 2001
From: austin <austinhc@tw.ibm.com>
Date: Mon, 13 May 2019 11:14:11 +0800
Subject: [PATCH] check save-prefix satisfies requested version range

---
 lib/install/deps.js | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/install/deps.js b/lib/install/deps.js
index 3fe370140adc3..ff6731f938895 100644
--- a/lib/install/deps.js
+++ b/lib/install/deps.js
@@ -318,7 +318,18 @@ function computeVersionSpec (tree, child) {
     if (semver.valid(version, true) &&
         semver.gte(version, '0.1.0', true) &&
         !npm.config.get('save-exact')) {
-      rangeDescriptor = npm.config.get('save-prefix')
+      if (requested.type === 'range') {
+        // add save-prefix '^' or '~' only when the future candidates satisfies the
+        // requested range version spec
+        var futureVersion = semver.maxSatisfying([semver.inc(version, 'major'),
+          semver.inc(version, 'minor'), semver.inc(version, 'patch')],
+        npm.config.get('save-prefix') + version)
+        if (semver.satisfies(futureVersion, requested.fetchSpec)) {
+          rangeDescriptor = npm.config.get('save-prefix')
+        }
+      } else {
+        rangeDescriptor = npm.config.get('save-prefix')
+      }
     }
     if (requested.type === 'alias') {
       rangeDescriptor = `npm:${requested.subSpec.name}@${rangeDescriptor}`