From d09796e265325024f1371fd43543cd1de7be6d20 Mon Sep 17 00:00:00 2001
From: Aleksey Pivovarov <AMPivovarov@gmail.com>
Date: Tue, 26 Jul 2022 11:23:17 +0200
Subject: [PATCH] lst: recover from catastrophic tracker refresh failure

Improve debug logging for "EA-259651 IOOBE: DiffUtil.getLines"

GitOrigin-RevId: 927cae250ee974d91bc34f9eb149ec72b35f9f92
---
 .../openapi/editor/impl/DocumentImpl.java     |  6 ++-
 .../openapi/vcs/ex/DocumentTracker.kt         | 42 ++++++++++++++++---
 2 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/platform/core-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java b/platform/core-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
index 0346cb8ebd75..df48cc6cc8ff 100644
--- a/platform/core-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
+++ b/platform/core-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
@@ -1202,7 +1202,11 @@ public final class DocumentImpl extends UserDataHolderBase implements DocumentEx
 
   @Override
   public String toString() {
-    return "DocumentImpl[" + FileDocumentManager.getInstance().getFile(this) + (isInEventsHandling() ? ",inEventHandling" : "") + "]";
+    return "DocumentImpl[" + FileDocumentManager.getInstance().getFile(this) +
+           (isInEventsHandling() ? ",inEventHandling" : "") +
+           (!myAssertThreading ? ",nonWriteThreadOnly" : "") +
+           (myAcceptSlashR ? ",acceptSlashR" : "") +
+           "]";
   }
 
   @NotNull
diff --git a/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt b/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
index 808818271a3b..6e3ae5115620 100644
--- a/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
+++ b/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
@@ -13,15 +13,18 @@ import com.intellij.openapi.Disposable
 import com.intellij.openapi.application.ApplicationListener
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.diagnostic.Logger
+import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.editor.Document
 import com.intellij.openapi.editor.event.DocumentEvent
 import com.intellij.openapi.editor.event.DocumentListener
+import com.intellij.openapi.progress.ProcessCanceledException
 import com.intellij.openapi.util.text.StringUtil
 import com.intellij.openapi.vcs.ex.DocumentTracker.Block
 import com.intellij.openapi.vcs.ex.DocumentTracker.Handler
 import com.intellij.util.concurrency.annotations.RequiresEdt
 import com.intellij.util.containers.PeekableIteratorWrapper
 import org.jetbrains.annotations.ApiStatus
+import java.util.*
 import java.util.concurrent.locks.ReentrantLock
 import kotlin.concurrent.withLock
 import kotlin.math.max
@@ -174,11 +177,25 @@ class DocumentTracker(
         return
       }
 
-      tracker.refreshDirty(document1.immutableCharSequence,
-                           document2.immutableCharSequence,
-                           document1.lineOffsets,
-                           document2.lineOffsets,
-                           fastRefresh)
+      try {
+        tracker.refreshDirty(document1.immutableCharSequence,
+                             document2.immutableCharSequence,
+                             document1.lineOffsets,
+                             document2.lineOffsets,
+                             fastRefresh)
+      }
+      catch (e: ProcessCanceledException) {
+        throw e
+      }
+      catch (e: Throwable) {
+        logger<DocumentTracker>().error(
+          "document1: $document1, document2: $document2, " +
+          "isFrozen1: ${freezeHelper.isFrozen(Side.LEFT)}, isFrozen2: ${freezeHelper.isFrozen(Side.RIGHT)}, " +
+          "isBulk1: ${document1.isInBulkUpdate}, isBulk2: ${document2.isInBulkUpdate}",
+          e)
+
+        tracker.resetTrackerState(DiffUtil.getLineCount(document1), DiffUtil.getLineCount(document2))
+      }
     }
   }
 
@@ -583,6 +600,21 @@ private class LineTracker(private val handlers: List<Handler>,
     afterBulkRangeChange(isDirty)
   }
 
+  /**
+   * Reset to the simplest valid state. Hopefully, the next full refresh will be successful.
+   */
+  fun resetTrackerState(lineCount1: Int, lineCount2: Int) {
+    val fullRange = Range(0, lineCount1, 0, lineCount2)
+    val dirtyBlock = Block(fullRange, true, false)
+    onRangesChanged(emptyList(), dirtyBlock)
+
+    blocks = listOf(dirtyBlock)
+    isDirty = true
+    forceMergeNearbyBlocks = false
+
+    afterBulkRangeChange(isDirty)
+  }
+
   fun rangeChanged(side: Side, startLine: Int, beforeLength: Int, afterLength: Int) {
     val data = RangeChangeHandler().run(blocks, side, startLine, beforeLength, afterLength)