[git] IJPL-172508 Show current commit message in rebase conflict dialog

GitOrigin-RevId: 38ecdf5195a6ccdad4ee2efe3cfba7a2b9ccb185

platform/vcs-api/src/com/intellij/openapi/vcs/merge/MergeDialogCustomizer.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.vcs.merge
 
 import com.intellij.diff.DiffEditorTitleCustomizer
@@ -9,6 +9,7 @@ import com.intellij.openapi.vcs.FilePath
 import com.intellij.openapi.vcs.VcsBundle
 import com.intellij.openapi.vcs.history.VcsRevisionNumber
 import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.util.concurrency.annotations.RequiresBackgroundThread
 import org.jetbrains.annotations.ApiStatus
 
 /**
@@ -25,6 +26,7 @@ open class MergeDialogCustomizer {
    *
    * @param files the files that have conflicted changes and are shown in the dialog.
    */
+  @RequiresBackgroundThread
   open fun getMultipleFileMergeDescription(files: MutableCollection<VirtualFile>): @NlsContexts.Label String = ""
 
   /**

plugins/git4idea/shared/resources/messages/GitBundle.properties

@@ -1296,6 +1296,7 @@ merge.dialog.description.merge.label.text=Merging {0,choice,1#branch {1}|2#diver
 merge.dialog.description.rebase.with.hash.label.text=Rebasing{0,choice,0#|1# branch {1}} onto {2}
 merge.dialog.description.rebase.with.onto.branch.label.text=Rebasing{0,choice,0#|1# branch {1}} onto branch {2}{3,choice,0#|1#, revision {4}}
 merge.dialog.description.rebase.without.onto.info.label.text=Rebasing{0,choice,0#|1# branch {1}} onto diverging branches
+merge.dialog.description.rebase.conflict.current.commit=Current commit {0} made by {1}:
 merge.dialog.diff.left.title.cherry.pick.label.text=Local Changes
 merge.dialog.diff.left.title.default.branch.label.text=Your version, branch {0}
 merge.dialog.diff.left.title.rebase.label.text=Rebasing {0} from {1}

plugins/git4idea/src/git4idea/merge/GitDefaultMergeDialogCustomizer.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package git4idea.merge
 
 import com.intellij.diff.DiffEditorTitleCustomizer
@@ -8,6 +8,7 @@ import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.NlsContexts
 import com.intellij.openapi.util.NlsSafe
 import com.intellij.openapi.util.text.HtmlBuilder
+import com.intellij.openapi.util.text.HtmlChunk
 import com.intellij.openapi.util.text.HtmlChunk.br
 import com.intellij.openapi.util.text.HtmlChunk.text
 import com.intellij.openapi.util.text.StringUtil
@@ -67,7 +68,13 @@ internal open class GitDefaultMergeDialogCustomizer(
     if (rebaseOntoBranches.isNotEmpty()) {
       val singleCurrentBranch = getSingleCurrentBranchName(repos)
       val singleOntoBranch = rebaseOntoBranches.toSet().singleOrNull()
-      return getDescriptionForRebase(singleCurrentBranch, singleOntoBranch?.branchName, singleOntoBranch?.hash)
+      val singleRepo = repos.singleOrNull()
+      return getDescriptionForRebase(
+        singleRepo,
+        singleCurrentBranch,
+        singleOntoBranch?.branchName,
+        singleOntoBranch?.hash,
+      )
     }
 
     val cherryPickCommitDetails = repos.mapNotNull { loadCherryPickCommitDetails(it) }
@@ -78,7 +85,7 @@ internal open class GitDefaultMergeDialogCustomizer(
         cherryPickCommitDetails.size, text(cherryPickCommitDetails.single().shortHash).code(),
         (singleCherryPick != null).toInt(),
         text(singleCherryPick?.authorName ?: ""),
-        HtmlBuilder().append(br()).append(text(singleCherryPick?.commitMessage ?: "").code())
+        HtmlBuilder().append(br()).append(CommitMessagePreview.asHtmlChunk (singleCherryPick?.commitMessage ?: ""))
       )
     }
 
@@ -178,37 +185,56 @@ internal open class GitDefaultMergeDialogCustomizer(
   }
 
   private fun loadCherryPickCommitDetails(repository: GitRepository): CherryPickDetails? {
-    val cherryPickHead = tryResolveRef(repository, CHERRY_PICK_HEAD) ?: return null
-
-    val shortDetails = GitLogUtil.collectMetadata(project, repository.root, listOf(cherryPickHead.asString()))
-
-    val result = shortDetails.singleOrNull() ?: return null
-    return CherryPickDetails(cherryPickHead.toShortString(), result.author.name, result.subject)
+    val result = GitLogUtil.collectMetadata(project, repository.root, listOf(CHERRY_PICK_HEAD)).singleOrNull() ?: return null
+    return CherryPickDetails(result.id.toShortString(), result.author.name, result.fullMessage)
   }
 
   private data class CherryPickDetails(@NlsSafe val shortHash: String, @NlsSafe val authorName: String, @NlsSafe val commitMessage: String)
 }
 
 @NlsContexts.Label
-internal fun getDescriptionForRebase(@NlsSafe rebasingBranch: String?, @NlsSafe baseBranch: String?, baseHash: Hash?): String =
-  when {
-    baseBranch != null -> html(
+internal fun getDescriptionForRebase(repository: GitRepository?, @NlsSafe rebasingBranch: String?, @NlsSafe baseBranch: String?, baseHash: Hash?): String {
+  val description = when {
+    baseBranch != null -> GitBundle.message(
       "merge.dialog.description.rebase.with.onto.branch.label.text",
       (rebasingBranch != null).toInt(), text(rebasingBranch ?: "").bold(),
       text(baseBranch).bold(),
       (baseHash != null).toInt(), baseHash?.toShortString() ?: ""
     )
-    baseHash != null -> html(
+    baseHash != null -> GitBundle.message(
       "merge.dialog.description.rebase.with.hash.label.text",
       (rebasingBranch != null).toInt(), text(rebasingBranch ?: "").bold(),
       text(baseHash.toShortString()).bold()
     )
-    else -> html(
+    else -> GitBundle.message(
       "merge.dialog.description.rebase.without.onto.info.label.text",
       (rebasingBranch != null).toInt(), text(rebasingBranch ?: "").bold()
     )
   }
 
+  val conflictOnCommit =
+    if (repository != null) GitLogUtil.collectMetadata(repository.project, repository.root, listOf(REBASE_HEAD)).singleOrNull()
+    else null
+
+  return if (conflictOnCommit == null) HtmlChunk.raw(description).toString()
+  else appendCommitMessageToRebaseConflictDescription(description, conflictOnCommit)
+}
+
+private fun appendCommitMessageToRebaseConflictDescription(description: @Nls String, conflictOnCommit: VcsCommitMetadata): @NlsSafe String {
+  val currentCommitDetails = GitBundle.message(
+    "merge.dialog.description.rebase.conflict.current.commit",
+    text(conflictOnCommit.id.toShortString()).code(),
+    conflictOnCommit.author.name
+  )
+
+  return HtmlBuilder()
+    .append(HtmlChunk.raw("$description. $currentCommitDetails"))
+    .br()
+    .append(CommitMessagePreview.asHtmlChunk(conflictOnCommit.fullMessage))
+    .wrapWith(HtmlChunk.html())
+    .toString()
+}
+
 internal fun getDefaultLeftPanelTitleForBranch(@NlsSafe branchName: String): String =
   html("merge.dialog.diff.left.title.default.branch.label.text", text(branchName).bold())
 
@@ -388,4 +414,22 @@ private class MergeConflictMultipleCommitInfoDialog(
 private data class RefInfo(val hash: Hash, @NlsSafe val branchName: String?) {
   @NlsSafe
   val presentable: String = branchName ?: hash.toShortString()
+}
+
+private object CommitMessagePreview {
+  private const val MAX_LINES = 3
+
+  fun asHtmlChunk(commitMessage: @NlsSafe String): HtmlChunk.Element =
+    HtmlChunk.text(trimAndEscape(commitMessage)).wrapWith("pre")
+
+  private fun trimAndEscape(commitMessage: @NlsSafe String): @NlsSafe String {
+    val lines = commitMessage.lines()
+    val trimmedMessage = if (lines.size <= MAX_LINES) {
+      commitMessage
+    } else {
+      lines.take(MAX_LINES).dropLastWhile { it.isBlank() }.joinToString("\n") + StringUtil.ELLIPSIS
+    }
+
+    return StringUtil.escapeXmlEntities(trimmedMessage)
+  }
 }

plugins/git4idea/src/git4idea/rebase/conflict/GitRebaseMergeDialogCustomizer.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package git4idea.rebase.conflict
 
 import com.intellij.diff.DiffEditorTitleCustomizer
@@ -95,7 +95,9 @@ private class GitRebaseMergeDialogCustomizer(
     }
   }
 
-  override fun getMultipleFileMergeDescription(files: MutableCollection<VirtualFile>) = getDescriptionForRebase(rebasingBranch, baseBranch, baseHash)
+  override fun getMultipleFileMergeDescription(files: MutableCollection<VirtualFile>) = getDescriptionForRebase(
+    repository, rebasingBranch, baseBranch, baseHash
+  )
 
   override fun getLeftPanelTitle(file: VirtualFile) = getDefaultLeftPanelTitleForBranch(rebasingBranch)