Memory leak with ICU 72.1.0.2 (Windows 11 24H2)

Hello,

We have a memory leak with ICU 72.1.0.2 on Windows 11 24H2. This doesn't happen with ICU 68.2.0.10 on Windows 11 23H2.

Here are the steps in a gui program with a File / Save As command:

• LoadLibrary('icuuc.dll')
• Get the addresses of u_init, u_cleanup, and u_setMemoryFunctions
• LoadLibrary ('icuin.dll'). This loads icu.dll too.
• Get the addresses of ucol_open, ucol_close, ucol_strcoll, and ucol_setAttribute
• Call u_setMemoryFunctions to set memory allocation functions
• Call u_init. The memory allocation functions are called
• Open a Save As dialog (GetSaveFileName, comdlg32.dll) and cancel
• Call u_cleanup (). This doesn't release memory allocated by u_init
• Call FreeLibray for icuin.dll. icu.dll is not unloaded and memory is not released
• Note that at this step if you haven't called GetSaveFileName, icu.dll is unloaded and the memory is released
• Call FreeLibrary for icuuc.dll. No change.

Regards,

Michel Terrisse

Start by reproducing the Windows sequence in the issue with ICU 72.1.0.2: load icuuc.dll and icuin.dll, call u_setMemoryFunctions, u_init, open and cancel GetSaveFileName, then call u_cleanup and FreeLibrary. Compare the unload and memory behavior with ICU 68.2.0.10; done means the reported allocations are released after cleanup and DLL unloading.