Revert "Change SDK/DartEditor versioning scheme to semantic versions."

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

Index: dart/sdk/lib/_internal/pub/lib/src/sdk.dart
diff --git a/dart/sdk/lib/_internal/pub/lib/src/sdk.dart b/dart/sdk/lib/_internal/pub/lib/src/sdk.dart
index bd8314b2062d891a77dd073c687324f759cabd43..c99f516a3a57077265bba483aa0854240612d470 100644
--- a/dart/sdk/lib/_internal/pub/lib/src/sdk.dart
+++ b/dart/sdk/lib/_internal/pub/lib/src/sdk.dart
@@ -12,6 +12,11 @@ import 'package:path/path.dart' as path;
 import 'io.dart';
 import 'version.dart';
 
+/// Matches an Eclipse-style SDK version number. This is four dotted numbers
+/// (major, minor, patch, build) with an optional suffix attached to the build
+/// number.
+final _versionPattern = new RegExp(r'^(\d+)\.(\d+)\.(\d+)\.(\d+.*)$');
+
 /// Gets the path to the root directory of the SDK.
 String get rootDirectory {
   // Assume the Dart executable is always coming from the SDK.
@@ -24,6 +29,30 @@ String get rootDirectory {
 /// different SDK versions.
 Version version = _getVersion();
 
+/// Is `true` if the current SDK is an unreleased bleeding edge version.
+bool get isBleedingEdge {
+  // The live build is locked to the magical old number "0.1.2+<stuff>".
+  return version.major == 0 && version.minor == 1 && version.patch == 2;
+}
+
+/// Parse an Eclipse-style version number using the SDK's versioning convention.
+Version parseVersion(String version) {
+  // Given a version file like: 0.1.2.0_r17495
+  // We create a semver like:   0.1.2+0.r17495
+  var match = _versionPattern.firstMatch(version);
+  if (match == null) {
+    throw new FormatException("The Dart SDK's 'version' file was not in a "
+        "format pub could recognize. Found: $version");
+  }
+
+  // Semantic versions cannot use "_".
+  var build = match[4].replaceAll('_', '.');
+
+  return new Version(
+      int.parse(match[1]), int.parse(match[2]), int.parse(match[3]),
+      build: build);
+}
+
 /// Determine the SDK's version number.
 Version _getVersion() {
   // Some of the pub integration tests require an SDK version number, but the
@@ -35,5 +64,5 @@ Version _getVersion() {
   // Read the "version" file.
   var revisionPath = path.join(rootDirectory, "version");
   var version = readTextFile(revisionPath).trim();
-  return new Version.parse(version);
+  return parseVersion(version);
 }