From c30e7b54e082cae3b73def7257d9f2aef0295b68 Mon Sep 17 00:00:00 2001
From: Yaroslav Lepenkin <yaroslav.lepenkin@jetbrains.com>
Date: Tue, 27 Oct 2015 18:26:30 +0300
Subject: [PATCH] Implemented simple check for alignment infinite recusrsion -
 we limit amount of backward block rollbacks (when we switch myCurrentBlock to
 some previously located block) to the number of total blocks with alignments.

---
 .../AbstractBlockAlignmentProcessor.java          |  2 +-
 .../com/intellij/formatting/FormatProcessor.java  | 15 ++++++++++++++-
 .../intellij/formatting/InitialInfoBuilder.java   |  9 +++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/formatting/AbstractBlockAlignmentProcessor.java b/platform/lang-impl/src/com/intellij/formatting/AbstractBlockAlignmentProcessor.java
index a66eceb51618..7740ea2a2603 100644
--- a/platform/lang-impl/src/com/intellij/formatting/AbstractBlockAlignmentProcessor.java
+++ b/platform/lang-impl/src/com/intellij/formatting/AbstractBlockAlignmentProcessor.java
@@ -135,7 +135,7 @@ public abstract class AbstractBlockAlignmentProcessor implements BlockAlignmentP
    */
   protected abstract int getAlignmentIndentDiff(@NotNull IndentData alignmentAnchorIndent, @NotNull Context context);
 
-  private static void reportAlignmentProcessingError(Context context) {
+  protected static void reportAlignmentProcessingError(Context context) {
     ASTNode node = context.targetBlock.getNode();
     Language language = node != null ? node.getPsi().getLanguage() : null;
     LogMessageEx.error(LOG,
diff --git a/platform/lang-impl/src/com/intellij/formatting/FormatProcessor.java b/platform/lang-impl/src/com/intellij/formatting/FormatProcessor.java
index c3091e64828e..615bd0daf055 100644
--- a/platform/lang-impl/src/com/intellij/formatting/FormatProcessor.java
+++ b/platform/lang-impl/src/com/intellij/formatting/FormatProcessor.java
@@ -42,6 +42,8 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
 
+import static com.intellij.formatting.AbstractBlockAlignmentProcessor.*;
+
 public class FormatProcessor {
 
   private static final Map<Alignment.Anchor, BlockAlignmentProcessor> ALIGNMENT_PROCESSORS =
@@ -160,6 +162,8 @@ public class FormatProcessor {
   @NotNull
   private State myCurrentState;
   private MultiMap<ExpandableIndent, AbstractBlockWrapper> myExpandableIndents;
+  private int myTotalBlocksWithAlignments;
+  private int myBlockRollbacks;
 
   public FormatProcessor(final FormattingDocumentModel docModel,
                          Block rootBlock,
@@ -752,7 +756,15 @@ public class FormatProcessor {
         myBackwardShiftedAlignedBlocks.put(offsetResponsibleBlock, blocksCausedRealignment);
         blocksCausedRealignment.add(myCurrentBlock);
         storeAlignmentMapping(myCurrentBlock, offsetResponsibleBlock);
-        myCurrentBlock = offsetResponsibleBlock.getNextBlock();
+        
+        if (myBlockRollbacks > myTotalBlocksWithAlignments) {
+          reportAlignmentProcessingError(context);
+          return true;
+        }
+        else {
+          myCurrentBlock = offsetResponsibleBlock.getNextBlock();
+          myBlockRollbacks++;
+        }
         onCurrentLineChanged();
         return false;
       case RECURSION_DETECTED:
@@ -1398,6 +1410,7 @@ public class FormatProcessor {
       myLastWhiteSpace = new WhiteSpace(lastBlockOffset, false);
       myLastWhiteSpace.append(Math.max(lastBlockOffset, myWrapper.getEndOffset()), myModel, myDefaultIndentOption);
       myAlignmentsInsideRangesToModify = myWrapper.getAlignmentsInsideRangeToModify();
+      myTotalBlocksWithAlignments = myWrapper.getBlocksToAlign().values().size();
     }
   }
 
diff --git a/platform/lang-impl/src/com/intellij/formatting/InitialInfoBuilder.java b/platform/lang-impl/src/com/intellij/formatting/InitialInfoBuilder.java
index 46045c827735..b9db5823b859 100644
--- a/platform/lang-impl/src/com/intellij/formatting/InitialInfoBuilder.java
+++ b/platform/lang-impl/src/com/intellij/formatting/InitialInfoBuilder.java
@@ -77,6 +77,7 @@ class InitialInfoBuilder {
   private boolean myCollectAlignmentsInsideFormattingRange = false;
 
   private MultiMap<ExpandableIndent, AbstractBlockWrapper> myBlocksToForceChildrenIndent = new LinkedMultiMap<ExpandableIndent, AbstractBlockWrapper>();
+  private MultiMap<Alignment, Block> myBlocksToAlign = new MultiMap<Alignment, Block>();
 
   private InitialInfoBuilder(final Block rootBlock,
                              final FormattingDocumentModel model,
@@ -205,6 +206,10 @@ class InitialInfoBuilder {
       myAlignmentsInsideRangeToModify.add(rootBlock.getAlignment());
     }
 
+    if (rootBlock.getAlignment() != null) {
+      myBlocksToAlign.putValue(rootBlock.getAlignment(), rootBlock);
+    }
+
     ReadOnlyBlockInformationProvider previousProvider = myReadOnlyBlockInformationProvider;
     try {
       if (rootBlock instanceof ReadOnlyBlockInformationProvider) {
@@ -293,6 +298,10 @@ class InitialInfoBuilder {
     return myBlocksToForceChildrenIndent;
   }
   
+  public MultiMap<Alignment, Block> getBlocksToAlign() {
+    return myBlocksToAlign;
+  }
+  
   private void doIteration(@NotNull State state) {
     List<Block> subBlocks = state.parentBlock.getSubBlocks();
     final int subBlocksCount = subBlocks.size();