[PATCH v4 3/4] server: Remove source when renaming to a hardlink of itself.

[Gabriel Ivăncescu]

From: Gabriel Ivăncescu

Signed-off-by: Gabriel Ivăncescu 
---
 dlls/kernel32/tests/file.c |  2 --
 server/fd.c                | 58 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/dlls/kernel32/tests/file.c b/dlls/kernel32/tests/file.c
index 1ef43b269ac..b1f6e1c98d4 100644
--- a/dlls/kernel32/tests/file.c
+++ b/dlls/kernel32/tests/file.c
@@ -2184,9 +2184,7 @@ static void test_MoveFileA(void)
     }
     FindClose(hfind);
     ret = GetFileAttributesA(source);
-    todo_wine
     ok(ret == INVALID_FILE_ATTRIBUTES && GetLastError() == ERROR_FILE_NOT_FOUND, "GetFileAttributesA: error %ld\n", GetLastError());
-    if(ret != INVALID_FILE_ATTRIBUTES) DeleteFileA(source);
     ret = DeleteFileA(dest);
     ok(ret, "DeleteFileA: error %ld\n", GetLastError());

diff --git a/server/fd.c b/server/fd.c
index ce32e7f8397..aae39d7a721 100644
--- a/server/fd.c
+++ b/server/fd.c
@@ -2531,6 +2531,56 @@ static void set_fd_disposition( struct fd *fd, unsigned int flags )
         ((fd->options & FILE_DELETE_ON_CLOSE) ? FILE_DISPOSITION_DELETE : 0);
 }

+/* check if it's same file by path, and not a hardlink (inodes are assumed to be the same already) */
+static int is_same_file_by_path( char *name1, char *name2 )
+{
+    /* we check if (1) the directories they're in are the same and (2) they have the same name */
+    size_t pathlen1, pathlen2;
+    struct stat st, st2;
+    int stat_ret;
+    char *p;
+
+    /* get path len up to last component, ignoring trailing slashes */
+    for (pathlen1 = 0, p = name1; *p;)
+        if (*p++ == '/' && *p)
+            pathlen1 = p - name1;
+    if (pathlen1) {
+        name1[pathlen1 - 1] = '\0';
+        stat_ret = stat( name1, &st );
+        name1[pathlen1 - 1] = '/';
+        if (stat_ret || !S_ISDIR( st.st_mode ))
+            return 0;
+    }
+
+    for (pathlen2 = 0, p = name2; *p;)
+        if (*p++ == '/' && *p)
+            pathlen2 = p - name2;
+    if (pathlen2) {
+        name2[pathlen2 - 1] = '\0';
+        stat_ret = stat( name2, &st2 );
+        name2[pathlen2 - 1] = '/';
+        if (stat_ret || !S_ISDIR( st2.st_mode ))
+            return 0;
+    }
+
+    if (!pathlen1 || !pathlen2)
+    {
+        if (pathlen1 != pathlen2)
+            return 0;
+    }
+    else
+    {
+        if (st.st_ino != st2.st_ino || st.st_dev != st2.st_dev)
+            return 0;
+        name1 += pathlen1;
+        name2 += pathlen2;
+    }
+
+    /* compare ignoring trailing slashes */
+    while (*name1 == *name2 && *name1) name1++, name2++;
+    return *name1 == *name2 || (!*name1 && *name2 == '/') || (*name1 == '/' && !*name2);
+}
+
 /* set new name for the fd */
 static void set_fd_name( struct fd *fd, struct fd *root, const char *nameptr, data_size_t len,
                          struct unicode_str nt_name, int create_link, unsigned int flags )
@@ -2583,7 +2633,13 @@ static void set_fd_name( struct fd *fd, struct fd *root, const char *nameptr, da
     {
         if (!fstat( fd->unix_fd, &st2 ) && st.st_ino == st2.st_ino && st.st_dev == st2.st_dev)
         {
-            if (create_link && !replace) set_error( STATUS_OBJECT_NAME_COLLISION );
+            if (!create_link)
+            {
+                /* if it's not the "same" file (by path), it means it's a hardlink, so we need to remove the source */
+                if (!is_same_file_by_path( fd->unix_name, name ) && unlink( fd->unix_name ))
+                    file_set_error();
+            }
+            else if (!replace) set_error( STATUS_OBJECT_NAME_COLLISION );
             free( name );
             return;
         }