[libc++][format] Fixed println.blank_line.sh.cpp test on llvm-clang-win-x-* configurations

[H-G-Hristov]

Fix for issue: #87277 (comment)

The test fails on the windows to linux cross builders. The proposed resolution is to print some text. The issue is possibly due to the original test outputting a single \n character.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Hristo Hristov (H-G-Hristov)

Changes

Fix for issue: #87277 (comment)

---

Full diff: https://github.com/llvm/llvm-project/pull/88011.diff

1 Files Affected:

• (modified) libcxx/test/std/input.output/iostream.format/print.fun/println.blank_line.sh.cpp (+3-1)

diff --git a/libcxx/test/std/input.output/iostream.format/print.fun/println.blank_line.sh.cpp b/libcxx/test/std/input.output/iostream.format/print.fun/println.blank_line.sh.cpp
index 93c3563d501b20..a262c287108a4c 100644
--- a/libcxx/test/std/input.output/iostream.format/print.fun/println.blank_line.sh.cpp
+++ b/libcxx/test/std/input.output/iostream.format/print.fun/println.blank_line.sh.cpp
@@ -35,13 +35,15 @@
 
 // FILE_DEPENDENCIES: echo.sh
 // RUN: %{build}
-// RUN: %{exec} bash echo.sh -ne "\n" > %t.expected
+// RUN: %{exec} bash echo.sh -ne "println blank line test: \n" > %t.expected
 // RUN: %{exec} "%t.exe" > %t.actual
 // RUN: diff -u %t.actual %t.expected
 
 #include <print>
 
 int main(int, char**) {
+  // On some configurations the `diff -u` test fails if we print a single blank line character `\n`, so we print some text first.
+  std::print("println blank line test: ");
   std::println();
 
   return 0;

[mordante]

Thanks for the quick fix! LGTM!
Please give @vvereschaka some time to respond and possibly test the fix prior to landing.

[H-G-Hristov]

Thanks for the quick fix! LGTM! Please give @vvereschaka some time to respond and possibly test the fix prior to landing.

@mordante Thank you!
@vvereschaka If you approve this fix. Please feel free to merge it.

[vvereschaka]

@H-G-Hristov , @mordante
thank you for the fix. I'll test it during the next hour.

[vvereschaka]

The local test has passed successfully. Thanks once again.
I'm going to merge the fix.