Consider what happens if a program does:

fd = fopen("A")
link("A", "B")
unlink("A")
fchown(fd)

Assuming we can't use the database, in order to handle this correctly, 
we need to change the open fd to point at B when A us unlinked.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Upstream-Status: Pending

Index: git/ports/unix/guts/linkat.c
===================================================================
--- git.orig/ports/unix/guts/linkat.c
+++ git/ports/unix/guts/linkat.c
@@ -116,6 +116,7 @@
 	 * if the thing linked is a symlink.
 	 */
 	pseudo_client_op(OP_LINK, 0, -1, -1, newpath, &buf);
+	pseudo_client_linked_paths(oldpath, newpath);
 
 	errno = save_errno;
 
Index: git/pseudo_client.c
===================================================================
--- git.orig/pseudo_client.c
+++ git/pseudo_client.c
@@ -70,6 +70,8 @@ int pseudo_umask = 022;
 
 static char **fd_paths = NULL;
 static int nfds = 0;
+static char **linked_fd_paths = NULL;
+static int linked_nfds = 0;
 static const char **passwd_paths = NULL;
 static int npasswd_paths = 0;
 #ifdef PSEUDO_PROFILING
@@ -889,39 +891,70 @@ fd_path(int fd) {
 }
 
 static void
-pseudo_client_path(int fd, const char *path) {
+pseudo_client_path_set(int fd, const char *path, char ***patharray, int *len) {
 	if (fd < 0)
 		return;
 
-	if (fd >= nfds) {
+	if (fd >= *len) {
 		int i;
 		pseudo_debug(PDBGF_CLIENT, "expanding fds from %d to %d\n",
-			nfds, fd + 1);
-		fd_paths = realloc(fd_paths, (fd + 1) * sizeof(char *));
-		for (i = nfds; i < fd + 1; ++i)
-			fd_paths[i] = 0;
-		nfds = fd + 1;
+			*len, fd + 1);
+		(*patharray) = realloc((*patharray), (fd + 1) * sizeof(char *));
+		for (i = *len; i < fd + 1; ++i)
+			(*patharray)[i] = 0;
+		*len = fd + 1;
 	} else {
-		if (fd_paths[fd]) {
+		if ((*patharray)[fd]) {
 			pseudo_debug(PDBGF_CLIENT, "reopening fd %d [%s] -- didn't see close\n",
-				fd, fd_paths[fd]);
+				fd, (*patharray)[fd]);
 		}
 		/* yes, it is safe to free null pointers. yay for C89 */
-		free(fd_paths[fd]);
-		fd_paths[fd] = 0;
+		free((*patharray)[fd]);
+		(*patharray)[fd] = 0;
 	}
 	if (path) {
-		fd_paths[fd] = strdup(path);
+		(*patharray)[fd] = strdup(path);
+	}
+}
+
+static void
+pseudo_client_path(int fd, const char *path) {
+	pseudo_client_path_set(fd, path, &fd_paths, &nfds);
+}
+
+void
+pseudo_client_linked_paths(const char *oldpath, const char *newpath) {
+	int fd;
+	for (fd = 3; fd < nfds; ++fd) {
+		if (fd_paths[fd] && !strcmp(oldpath, fd_paths[fd])) {
+			pseudo_client_path_set(fd, newpath, &linked_fd_paths, &linked_nfds);
+		}
 	}
 }
 
 static void
+pseudo_client_unlinked_path(const char *path) {
+	int fd;
+	for (fd = 0; fd < linked_nfds; ++fd) {
+		if (linked_fd_paths[fd] && fd_paths[fd] && !strcmp(path, fd_paths[fd])) {
+			pseudo_client_path(fd, linked_fd_paths[fd]);
+		}
+	}
+}
+
+
+static void
 pseudo_client_close(int fd) {
 	if (fd < 0 || fd >= nfds)
 		return;
 
 	free(fd_paths[fd]);
 	fd_paths[fd] = 0;
+
+	if (fd < linked_nfds) {
+		free(linked_fd_paths[fd]);
+		linked_fd_paths[fd] = 0;
+	}
 }
 
 /* spawn server */
@@ -1860,6 +1893,12 @@ pseudo_client_op(pseudo_op_t op, int acc
 			dirfd);
 		pseudo_client_path(dirfd, fd_path(fd));
 		break;
+	case OP_UNLINK:
+	case OP_DID_UNLINK:
+		if (path)
+			pseudo_client_unlinked_path(path);
+		do_request = 1;
+		break;
 	/* operations for which we should use the magic uid/gid */
 	case OP_CHMOD:
 	case OP_CREAT:
@@ -1882,8 +1921,6 @@ pseudo_client_op(pseudo_op_t op, int acc
 	case OP_LINK:
 	case OP_RENAME:
 	case OP_STAT:
-	case OP_UNLINK:
-	case OP_DID_UNLINK:
 	case OP_CANCEL_UNLINK:
 	case OP_MAY_UNLINK:
 	case OP_GET_XATTR:
Index: git/pseudo_client.h
===================================================================
--- git.orig/pseudo_client.h
+++ git/pseudo_client.h
@@ -9,6 +9,7 @@
 extern pseudo_msg_t *pseudo_client_op(pseudo_op_t op, int access, int fd, int dirfd, const char *path, const PSEUDO_STATBUF *buf, ...);
 extern int pseudo_client_ignore_path(const char *path);
 extern int pseudo_client_ignore_fd(int fd);
+extern void pseudo_client_linked_paths(const char *oldpath, const char *newpath);
 #if PSEUDO_STATBUF_64
 #define base_lstat real_lstat64
 #define base_fstat real_fstat64