[libc-commits] [libc] [libc] Fix copy/paste error in file.cpp (PR #150802)

[via libc-commits]

https://github.com/codefaber updated https://github.com/llvm/llvm-project/pull/150802

>From 268d890d11e06ef28c4f2f51ed3dba98cae8c2a3 Mon Sep 17 00:00:00 2001
From: codefaber <codefaber>
Date: Sun, 27 Jul 2025 00:35:42 +0300
Subject: [PATCH 1/2] [libc] Fix copy/paste error in file.cpp

---
 libc/src/__support/File/file.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libc/src/__support/File/file.cpp b/libc/src/__support/File/file.cpp
index 303852dbbb717..4217e73828388 100644
--- a/libc/src/__support/File/file.cpp
+++ b/libc/src/__support/File/file.cpp
@@ -123,7 +123,7 @@ FileIOResult File::write_unlocked_fbf(const uint8_t *data, size_t len) {
 
     FileIOResult result =
         platform_write(this, remainder.data(), remainder.size());
-    size_t bytes_written = buf_result.value;
+    size_t bytes_written = result.value;
 
     // If less bytes were written than expected, then an error occurred. Return
     // the number of bytes that have been written from |data|.

>From b3f9c7a5aedbfd7a9fd120ba55556bb0836ac10f Mon Sep 17 00:00:00 2001
From: codefaber <codefaber>
Date: Sun, 3 Aug 2025 01:24:09 +0300
Subject: [PATCH 2/2] [libc] Implement test case for copy/paste error in
 file.cpp

---
 libc/test/src/__support/File/file_test.cpp | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/libc/test/src/__support/File/file_test.cpp b/libc/test/src/__support/File/file_test.cpp
index b3c9f2ba49bce..ba23b30b732b0 100644
--- a/libc/test/src/__support/File/file_test.cpp
+++ b/libc/test/src/__support/File/file_test.cpp
@@ -493,3 +493,22 @@ TEST(LlvmLibcFileTest, WriteNothing) {
   ASSERT_EQ(f_lbf->close(), 0);
   ASSERT_EQ(f_nbf->close(), 0);
 }
+
+TEST(LlvmLibcFileTest, WriteSplit)
+{
+  constexpr size_t FILE_BUFFER_SIZE = 8;
+  char file_buffer[FILE_BUFFER_SIZE];
+  StringFile *f =
+      new_string_file(file_buffer, FILE_BUFFER_SIZE, _IOFBF, false, "w");
+
+  static constexpr size_t AVAIL = 12;
+  f->seek(-AVAIL, SEEK_END);
+
+  const char data[] = "hello";
+  ASSERT_EQ(sizeof(data) - 1, f->write(data, sizeof(data) - 1).value);
+
+  const char data2[] = " extra data";
+  static constexpr size_t WR_EXPECTED = AVAIL - (sizeof(data) - 1);
+  ASSERT_EQ(WR_EXPECTED, f->write(data2, sizeof(data2) - 1).value);
+  EXPECT_TRUE(f->error());
+}