From: Johannes Schindelin <johannes.schindelin@xxxxxx> The FAT file system has no concept of ACLs. Therefore, it cannot store any ownership information anyway, and the `GetNamedSecurityInfoW()` call pretends that everything is owned "by the world". Let's special-case that scenario and tell the user what's going on. This addresses https://github.com/git-for-windows/git/issues/3886 Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> --- compat/mingw.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index 2c09c5bffee..22f960c7e34 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2674,6 +2674,21 @@ static PSID get_current_user_sid(void) return result; } +static int acls_supported(const char *path) +{ + size_t offset = offset_1st_component(path); + WCHAR wroot[MAX_PATH]; + DWORD file_system_flags; + + if (offset && + xutftowcsn(wroot, path, MAX_PATH, offset) > 0 && + GetVolumeInformationW(wroot, NULL, 0, NULL, NULL, + &file_system_flags, NULL, 0)) + return !!(file_system_flags & FILE_PERSISTENT_ACLS); + + return 0; +} + int is_path_owned_by_current_sid(const char *path, struct strbuf *report) { WCHAR wpath[MAX_PATH]; @@ -2721,7 +2736,15 @@ int is_path_owned_by_current_sid(const char *path, struct strbuf *report) IsValidSid(current_user_sid) && EqualSid(sid, current_user_sid)) result = 1; - else if (report) { + else if (report && + IsWellKnownSid(sid, WinWorldSid) && + !acls_supported(path)) { + /* + * On FAT32 volumes, ownership is not actually recorded. + */ + strbuf_addf(report, "'%s' is on a file system that does" + "not record ownership\n", path); + } else if (report) { LPSTR str1, str2, to_free1 = NULL, to_free2 = NULL; if (ConvertSidToStringSidA(sid, &str1)) -- gitgitgadget