From ddef5a2f929240905723ca7c527b6cb7edeb9eb9 Mon Sep 17 00:00:00 2001
From: Kirill Likhodedov <Kirill.Likhodedov@jetbrains.com>
Date: Sat, 9 May 2015 11:38:36 +0300
Subject: [PATCH] [git] IDEA-140051 Avoid SIOOBE is the hash is too short for
 some reason

+ remove some obsolete code;
+ add diagnostics for hashes with unexpected length.
---
 .../dvcs-impl/src/com/intellij/dvcs/DvcsUtil.java   | 13 +++++++------
 .../git4idea/src/git4idea/branch/GitBranchUtil.java |  2 +-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/platform/dvcs-impl/src/com/intellij/dvcs/DvcsUtil.java b/platform/dvcs-impl/src/com/intellij/dvcs/DvcsUtil.java
index 47303f694796..96bba328b8c9 100644
--- a/platform/dvcs-impl/src/com/intellij/dvcs/DvcsUtil.java
+++ b/platform/dvcs-impl/src/com/intellij/dvcs/DvcsUtil.java
@@ -71,6 +71,7 @@ public class DvcsUtil {
   private static final Logger LOGGER = Logger.getInstance(DvcsUtil.class);
   private static final int IO_RETRIES = 3; // number of retries before fail if an IOException happens during file read.
   private static final int SHORT_HASH_LENGTH = 8;
+  private static final int LONG_HASH_LENGTH = 40;
 
   public static void installStatusBarWidget(@NotNull Project project, @NotNull StatusBarWidget widget) {
     StatusBar statusBar = WindowManager.getInstance().getStatusBar(project);
@@ -163,13 +164,13 @@ public class DvcsUtil {
 
   @NotNull
   public static String getShortHash(@NotNull String hash) {
-    if (hash.length() == 0) return "";
-    if (hash.length() == 40) return hash.substring(0, SHORT_HASH_LENGTH);
-    if (hash.length() > 40)  // revision string encoded with date too
-    {
-      return hash.substring(hash.indexOf("[") + 1, SHORT_HASH_LENGTH);
+    if (hash.length() < SHORT_HASH_LENGTH) {
+      LOG.debug("Unexpectedly short hash: [" + hash + "]");
     }
-    return hash;
+    if (hash.length() > LONG_HASH_LENGTH) {
+      LOG.debug("Unexpectedly long hash: [" + hash + "]");
+    }
+    return hash.substring(0, Math.min(SHORT_HASH_LENGTH, hash.length()));
   }
 
   @NotNull
diff --git a/plugins/git4idea/src/git4idea/branch/GitBranchUtil.java b/plugins/git4idea/src/git4idea/branch/GitBranchUtil.java
index ceddd8fca5aa..e5cbd84cde27 100644
--- a/plugins/git4idea/src/git4idea/branch/GitBranchUtil.java
+++ b/plugins/git4idea/src/git4idea/branch/GitBranchUtil.java
@@ -271,7 +271,7 @@ public class GitBranchUtil {
     if (state == GitRepository.State.DETACHED) {
       String currentRevision = repository.getCurrentRevision();
       assert currentRevision != null : "Current revision can't be null in DETACHED state, only on the fresh repository.";
-      return currentRevision.substring(0, 7);
+      return DvcsUtil.getShortHash(currentRevision);
     }
 
     String prefix = "";