[PATCH V4 1/1] Replace SID with domain/username

["Sören Krecker" <soekkle@freenet.de>]

Replace SID with domain/username in error message, if owner of repository
and user are not equal on windows systems. Each user should have a unique
SID (https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/manage/understand-security-identifiers#what-are-security-identifiers).
This means that domain/username is not a loss of information. If the translation
fails the message contains the SID as string.

Old Prompted error message:
'''
fatal: detected dubious ownership in repository at 'C:/Users/test/source/repos/git'
'C:/Users/test/source/repos/git' is owned by:
	'S-1-5-21-571067702-4104414259-3379520149-500'
but the current user is:
	'S-1-5-21-571067702-4104414259-3379520149-1001'
To add an exception for this directory, call:

	git config --global --add safe.directory C:/Users/test/source/repos/git
'''

New prompted error massage:
'''
fatal: detected dubious ownership in repository at 'C:/Users/test/source/repos/git'
'C:/Users/test/source/repos/git' is owned by:
	'DESKTOP-L78JVA6/Administrator'
but the current user is:
	'DESKTOP-L78JVA6/test'
To add an exception for this directory, call:

	git config --global --add safe.directory C:/Users/test/source/repos/git
'''

Signed-off-by: Sören Krecker <soekkle@freenet.de>
---
 compat/mingw.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index 42053c1f65..bfd9573a29 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2684,6 +2684,27 @@ static PSID get_current_user_sid(void)
 	return result;
 }
 
+static BOOL user_sid_to_user_name(PSID sid, LPSTR *str)
+{
+	SID_NAME_USE pe_use;
+	DWORD len_user = 0, len_domain = 0;
+	BOOL translate_sid_to_user;
+
+	/* returns only FALSE, because the string pointers are NULL*/
+	LookupAccountSidA(NULL, sid, NULL, &len_user, NULL, &len_domain,
+			  &pe_use); 
+	/*Alloc needed space of the strings*/
+	ALLOC_ARRAY((*str), (size_t)len_domain + (size_t)len_user); 
+	translate_sid_to_user = LookupAccountSidA(NULL, sid, (*str) + len_domain, &len_user,
+				   *str, &len_domain, &pe_use);
+	if (translate_sid_to_user == FALSE) {
+		FREE_AND_NULL(*str);
+	}
+	else
+		(*str)[len_domain] = '/';
+	return translate_sid_to_user;
+}
+
 static int acls_supported(const char *path)
 {
 	size_t offset = offset_1st_component(path);
@@ -2767,7 +2788,9 @@ int is_path_owned_by_current_sid(const char *path, struct strbuf *report)
 		} else if (report) {
 			LPSTR str1, str2, to_free1 = NULL, to_free2 = NULL;
 
-			if (ConvertSidToStringSidA(sid, &str1))
+			if (user_sid_to_user_name(sid, &str1))
+				to_free1 = str1;
+			else if (ConvertSidToStringSidA(sid, &str1))
 				to_free1 = str1;
 			else
 				str1 = "(inconvertible)";
@@ -2776,7 +2799,10 @@ int is_path_owned_by_current_sid(const char *path, struct strbuf *report)
 				str2 = "(none)";
 			else if (!IsValidSid(current_user_sid))
 				str2 = "(invalid)";
-			else if (ConvertSidToStringSidA(current_user_sid, &str2))
+			else if (user_sid_to_user_name(current_user_sid, &str2))
+				to_free2 = str2;
+			else if (ConvertSidToStringSidA(current_user_sid,
+							&str2))
 				to_free2 = str2;
 			else
 				str2 = "(inconvertible)";
@@ -2784,8 +2810,8 @@ int is_path_owned_by_current_sid(const char *path, struct strbuf *report)
 				    "'%s' is owned by:\n"
 				    "\t'%s'\nbut the current user is:\n"
 				    "\t'%s'\n", path, str1, str2);
-			LocalFree(to_free1);
-			LocalFree(to_free2);
+			free(to_free1);
+			free(to_free2);
 		}
 	}
 
-- 
2.39.2