check save-prefix satisfies requested version range

Author: austinhc-ibm

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}`