From: Vladimir Kikhtenko <kikht@yandex-team.ru>
Date: Fri, 18 Nov 2022 06:46:18 +0000 (+0600)
Subject: Use FILE_SHARE_WRITE and FILE_SHARE_DELETE when opening files on Windows
X-Git-Tag: v3.6.2~16^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F1806%2Fhead;p=thirdparty%2Flibarchive.git

Use FILE_SHARE_WRITE and FILE_SHARE_DELETE when opening files on Windows

Many standard libraries(
[libc++](https://github.com/llvm/llvm-project/blob/main/libcxx/src/filesystem/posix_compat.h#L159),
[go](https://cs.opensource.google/go/go/+/refs/tags/go1.19.3:src/syscall/syscall_windows.go;l=331),
[rust](https://doc.rust-lang.org/src/std/os/windows/fs.rs.html#126-131)
) open files on windows with `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`
mode by default. Libarchive uses only `FILE_SHARE_READ`, so when file is
being opened by any program that uses these standard libraries
libarchive fails to open it. Here we change libarchive shared flags, so
it plays well with common practice in other programs.
---

diff --git a/libarchive/archive_read_disk_windows.c b/libarchive/archive_read_disk_windows.c
index ea32e2aac..f9d139557 100644
--- a/libarchive/archive_read_disk_windows.c
+++ b/libarchive/archive_read_disk_windows.c
@@ -418,8 +418,9 @@ la_linkname_from_pathw(const wchar_t *path, wchar_t **outbuf, int *linktype)
 	    FILE_FLAG_OPEN_REPARSE_POINT;
 	int ret;
 
-	h = CreateFileW(path, 0, FILE_SHARE_READ, NULL, OPEN_EXISTING, flag,
-	    NULL);
+	h = CreateFileW(path, 0,
+	    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+	    OPEN_EXISTING, flag, NULL);
 	if (h == INVALID_HANDLE_VALUE) {
 		la_dosmaperr(GetLastError());
 		return (-1);
@@ -1073,7 +1074,9 @@ next_entry(struct archive_read_disk *a, struct tree *t,
 		else
 			flags |= FILE_FLAG_SEQUENTIAL_SCAN;
 		t->entry_fh = CreateFileW(tree_current_access_path(t),
-		    GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, flags, NULL);
+		    GENERIC_READ,
+		    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+		    NULL, OPEN_EXISTING, flags, NULL);
 		if (t->entry_fh == INVALID_HANDLE_VALUE) {
 			la_dosmaperr(GetLastError());
 			archive_set_error(&a->archive, errno,
@@ -2046,7 +2049,8 @@ tree_current_file_information(struct tree *t, BY_HANDLE_FILE_INFORMATION *st,
 	
 	if (sim_lstat && tree_current_is_physical_link(t))
 		flag |= FILE_FLAG_OPEN_REPARSE_POINT;
-	h = CreateFileW(tree_current_access_path(t), 0, FILE_SHARE_READ, NULL,
+	h = CreateFileW(tree_current_access_path(t), 0,
+	    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
 	    OPEN_EXISTING, flag, NULL);
 	if (h == INVALID_HANDLE_VALUE) {
 		la_dosmaperr(GetLastError());
@@ -2275,7 +2279,8 @@ archive_read_disk_entry_from_file(struct archive *_a,
 			} else
 				desiredAccess = GENERIC_READ;
 
-			h = CreateFileW(path, desiredAccess, FILE_SHARE_READ, NULL,
+			h = CreateFileW(path, desiredAccess,
+			    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
 			    OPEN_EXISTING, flag, NULL);
 			if (h == INVALID_HANDLE_VALUE) {
 				la_dosmaperr(GetLastError());
@@ -2337,7 +2342,8 @@ archive_read_disk_entry_from_file(struct archive *_a,
 		if (fd >= 0) {
 			h = (HANDLE)_get_osfhandle(fd);
 		} else {
-			h = CreateFileW(path, GENERIC_READ, FILE_SHARE_READ, NULL,
+			h = CreateFileW(path, GENERIC_READ,
+			    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
 			    OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
 			if (h == INVALID_HANDLE_VALUE) {
 				la_dosmaperr(GetLastError());