Don't allow pre-release versions of the max in "<" constraints.

sdk/lib/_internal/pub/lib/src/version.dart

Index: sdk/lib/_internal/pub/lib/src/version.dart
diff --git a/sdk/lib/_internal/pub/lib/src/version.dart b/sdk/lib/_internal/pub/lib/src/version.dart
index 50cfb0c57123c22b22bbf0f65164932f6e1d86f9..b68c3eda4a854ef7e4822f1b5336c195ed90353e 100644
--- a/sdk/lib/_internal/pub/lib/src/version.dart
+++ b/sdk/lib/_internal/pub/lib/src/version.dart
@@ -474,10 +474,27 @@ class VersionRange implements VersionConstraint {
 
   /// Tests if [other] matches falls within this version range.
   bool allows(Version other) {
-    if (min != null && other < min) return false;
-    if (min != null && !includeMin && other == min) return false;
-    if (max != null && other > max) return false;
-    if (max != null && !includeMax && other == max) return false;
+    if (min != null) {
+      if (other < min) return false;
+      if (!includeMin && other == min) return false;
+    }
+
+    if (max != null) {
+      if (other > max) return false;
+      if (!includeMax && other == max) return false;
+
+      // If the max isn't itself a pre-release, don't allow any pre-release
+      // versions of the max.
+      //
+      // See: https://www.npmjs.org/doc/misc/semver.html
+      if (!includeMax &&
+          !max.isPreRelease && other.isPreRelease &&
+          other.major == max.major && other.minor == max.minor &&
+          other.patch == max.patch) {
+        return false;
+      }
+    }
+
     return true;
   }