mingw: provide details about unsafe directories' ownership

When Git refuses to use an existing repository because it is owned by
someone else than the current user, it can be a bit tricky on Windows to
figure out what is going on.

Let's help with that by providing more detailed information.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/mingw.c b/compat/mingw.c
index f12b7df16d91956c07ea99de8fbe52dbd3173f2a..2c09c5bffee006f8904c2aa0f9ee9eb60841bfaf 100644 (file)
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1,6 +1,7 @@
 #include "../git-compat-util.h"
 #include "win32.h"
 #include <aclapi.h>
+#include <sddl.h>
 #include <conio.h>
 #include <wchar.h>
 #include "../strbuf.h"
@@ -2720,6 +2721,29 @@ 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) {
+                       LPSTR str1, str2, to_free1 = NULL, to_free2 = NULL;
+
+                       if (ConvertSidToStringSidA(sid, &str1))
+                               to_free1 = str1;
+                       else
+                               str1 = "(inconvertible)";
+
+                       if (!current_user_sid)
+                               str2 = "(none)";
+                       else if (!IsValidSid(current_user_sid))
+                               str2 = "(invalid)";
+                       else if (ConvertSidToStringSidA(current_user_sid, &str2))
+                               to_free2 = str2;
+                       else
+                               str2 = "(inconvertible)";
+                       strbuf_addf(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);
+               }
        }
 
        /*