Prepend zeros to package part hash code

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/kotlin/PackagePartClassUtils.java

@@ -56,8 +56,12 @@ public class PackagePartClassUtils {
         String fileName = FileUtil.getNameWithoutExtension(PathUtil.getFileName(file.getName()));
 
         // path hashCode to prevent same name / different path collision
-        String srcName = facadeFqName.shortName().asString() + "$" + replaceSpecialSymbols(fileName) + "$" + Integer.toHexString(
+        String srcName = String.format(
-                getPathHashCode(file));
+                "%s$%s$%08x",
+                facadeFqName.shortName().asString(),
+                replaceSpecialSymbols(fileName),
+                getPathHashCode(file)
+        );
 
         return facadeFqName.parent().child(Name.identifier(srcName));
     }

jps-plugin/test/org/jetbrains/jet/jps/build/AbstractIncrementalJpsTest.kt

@@ -252,8 +252,8 @@ public abstract class AbstractIncrementalJpsTest : JpsBuildTestCase() {
         }
 
         class object {
-            // We suspect sequences of several consecutive hexadecimal digits to be a package part hash code
+            // We suspect sequences of eight consecutive hexadecimal digits to be a package part hash code
-            val STRIP_PACKAGE_PART_HASH_PATTERN = Pattern.compile("\\$([0-9a-f]{5,8})")
+            val STRIP_PACKAGE_PART_HASH_PATTERN = Pattern.compile("\\$([0-9a-f]{8})")
         }
     }