[clang] [clang-format] Do not update cursor pos if no includes replacement (PR #77456)

[via cfe-commits]

https://github.com/NorthBlue333 updated https://github.com/llvm/llvm-project/pull/77456

>From 897c90c09f24b6fd8b0c84b57a284cabb77c9e80 Mon Sep 17 00:00:00 2001
From: NorthBlue333 <north333 at free.fr>
Date: Tue, 9 Jan 2024 14:01:14 +0100
Subject: [PATCH] [clang-format] Do not update cursor pos if no includes
 replacement

---
 clang/lib/Format/Format.cpp                 | 14 +++++++---
 clang/unittests/Format/SortIncludesTest.cpp | 31 +++++++++++++++++++++
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index f798d555bf9929..a91f6a639fb00b 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -3119,6 +3119,7 @@ static void sortCppIncludes(const FormatStyle &Style,
     return;
   }
 
+  unsigned NewCursor = UINT_MAX;
   std::string result;
   for (unsigned Index : Indices) {
     if (!result.empty()) {
@@ -3131,13 +3132,10 @@ static void sortCppIncludes(const FormatStyle &Style,
     }
     result += Includes[Index].Text;
     if (Cursor && CursorIndex == Index)
-      *Cursor = IncludesBeginOffset + result.size() - CursorToEOLOffset;
+      NewCursor = IncludesBeginOffset + result.size() - CursorToEOLOffset;
     CurrentCategory = Includes[Index].Category;
   }
 
-  if (Cursor && *Cursor >= IncludesEndOffset)
-    *Cursor += result.size() - IncludesBlockSize;
-
   // If the #includes are out of order, we generate a single replacement fixing
   // the entire range of blocks. Otherwise, no replacement is generated.
   if (replaceCRLF(result) == replaceCRLF(std::string(Code.substr(
@@ -3145,6 +3143,14 @@ static void sortCppIncludes(const FormatStyle &Style,
     return;
   }
 
+  if (Cursor) {
+    if (UINT_MAX != NewCursor) {
+      *Cursor = NewCursor;
+    } else if (*Cursor >= IncludesEndOffset) {
+      *Cursor += result.size() - IncludesBlockSize;
+    }
+  }
+
   auto Err = Replaces.add(tooling::Replacement(
       FileName, Includes.front().Offset, IncludesBlockSize, result));
   // FIXME: better error handling. For now, just skip the replacement for the
diff --git a/clang/unittests/Format/SortIncludesTest.cpp b/clang/unittests/Format/SortIncludesTest.cpp
index ec142e03b12854..652cd842e6f3f5 100644
--- a/clang/unittests/Format/SortIncludesTest.cpp
+++ b/clang/unittests/Format/SortIncludesTest.cpp
@@ -821,6 +821,37 @@ TEST_F(SortIncludesTest, CalculatesCorrectCursorPositionWithRegrouping) {
   EXPECT_EQ(27u, newCursor(Code, 28)); // Start of last line
 }
 
+TEST_F(SortIncludesTest, CalculatesCorrectCursorPositionWithRegrouping) {
+  Style.IncludeBlocks = Style.IBS_Regroup;
+  FmtStyle.LineEnding = FormatStyle::CRLF;
+  Style.IncludeCategories = {
+      {"^\"aa\"", 1, 0, false},
+      {"^\"b\"", 1, 1, false}
+      {".*", 2, 2, false}};
+  std::string Code = "#include \"aa\"\r\n" // Start of line: 0
+                     "\r\n"                // Start of line: 15
+                     "#include \"b\"\r\n"  // Start of line: 17
+                     "\r\n"                // Start of line: 31
+                     "#include \"c\"\r\n"  // Start of line: 33
+                     "\r\n"                // Start of line: 47
+                     "int i;";             // Start of line: 49
+  std::string Expected = "#include \"aa\"\r\n" // Start of line: 0
+                         "\r\n"                // Start of line: 15
+                         "#include \"b\"\r\n"  // Start of line: 17
+                         "\r\n"                // Start of line: 31
+                         "#include \"c\"\r\n"  // Start of line: 33
+                         "\r\n"                // Start of line: 47
+                         "int i;";             // Start of line: 49
+  EXPECT_EQ(Expected, sort(Code));
+  EXPECT_EQ(0u, newCursor(Code, 0));
+  EXPECT_EQ(15u, newCursor(Code, 15));
+  EXPECT_EQ(17u, newCursor(Code, 17));
+  EXPECT_EQ(31u, newCursor(Code, 31));
+  EXPECT_EQ(33u, newCursor(Code, 33));
+  EXPECT_EQ(47u, newCursor(Code, 47));
+  EXPECT_EQ(49u, newCursor(Code, 49));
+}
+
 TEST_F(SortIncludesTest, DeduplicateIncludes) {
   EXPECT_EQ("#include <a>\n"
             "#include <b>\n"