https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=d4a5c2be8bc09823b9afd4c6eafd41981e5ed645
commit d4a5c2be8bc09823b9afd4c6eafd41981e5ed645 Author: Corinna Vinschen <[email protected]> AuthorDate: Thu Feb 27 13:51:39 2025 +0100 Commit: Corinna Vinschen <[email protected]> CommitDate: Thu Feb 27 13:51:39 2025 +0100 Cygwin: fhandler_netdrive: fix character conversion required for NFS shares While filenames on NFS shares are converted internally to a widechar representation of the input bytes treated as the default system ANSI codepage (CP_ACP), this doesn't hold for share names. The names returned by WNetEnumResourceW are just the original bytes dropped verbatim into WCHAR. The original conversion from 7db1c6fc4e2a ("Cygwin: //server: revert to using WNet and support NFS shares") was erroneous in that it treated the bytes as ISO-8859-1, not as CP_ACP codepoints. Fix the conversion to convert from CP_ACP to widechar. Use a tmp_pathbuf buffer for the new widechar string instead of malloc/free. Extend the comment, better explaining the encoding difference between files and shares. Fixes: 7db1c6fc4e2a ("Cygwin: //server: revert to using WNet and support NFS shares") Signed-off-by: Corinna Vinschen <[email protected]> Diff: --- winsup/cygwin/fhandler/netdrive.cc | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/winsup/cygwin/fhandler/netdrive.cc b/winsup/cygwin/fhandler/netdrive.cc index 58447ed5aaab..426542fe212b 100644 --- a/winsup/cygwin/fhandler/netdrive.cc +++ b/winsup/cygwin/fhandler/netdrive.cc @@ -317,6 +317,7 @@ thread_netdrive_wnet (void *arg) size_t entry_cache_size = DIR_cache.count (); WCHAR provider[256], *dummy = NULL; wchar_t srv_name[CYG_MAX_PATH]; + wchar_t *nfs_namebuf = NULL; NETRESOURCEW nri = { 0 }; LPNETRESOURCEW nro; NETINFOSTRUCT netinfo; @@ -397,6 +398,10 @@ thread_netdrive_wnet (void *arg) ndi->err = ENOENT; goto out; } + /* We need a temporary buffer for the multibyte to widechar conversion + only required for NFS shares. */ + if (!nfs_namebuf) + nfs_namebuf = tp.w_get (); break; case WNNC_NET_DAV: /* WebDAV enumeration isn't supported, by the provider, but we can @@ -447,19 +452,21 @@ thread_netdrive_wnet (void *arg) if (net_type == WNNC_NET_MS_NFS) { - wchar_t *nm = name; - /* Convert from "ANSI embedded in widechar" to multibyte and convert - back to widechar. */ + /* With MS NFS, the bytes of the share name on the remote side + are simply dropped into a WCHAR buffer without conversion to + Unicode. So convert from "multibyte embedded in widechar" to + real multibyte and then convert back to widechar here. + + Quirky: This conversion is already performed for files on an + MS NFS filesystem when calling NtQueryDirectoryFile, but it's + not performed on the strings returned by WNetEnumResourceW. */ char mbname[wcslen (name) + 1]; char *mb = mbname; - while ((*mb++ = *nm++)) + while ((*mb++ = *name++)) ; - sys_mbstowcs_alloc (&name, HEAP_NOTHEAP, mbname); - if (!name) - { - ndi->err = ENOMEM; - goto out; - } + + name = nfs_namebuf; + MultiByteToWideChar (CP_ACP, 0, mbname, -1, name, NT_MAX_PATH); } /* Some providers have deep links so convert embedded '\\' to '/' here */ for (wchar_t *bs = name; (bs = wcschr (bs, L'\\')); *bs++ = L'/') @@ -470,8 +477,6 @@ thread_netdrive_wnet (void *arg) break; if (cache_idx >= entry_cache_size) DIR_cache.add (name); - if (net_type == WNNC_NET_MS_NFS) - free (name); } out: if (dom)
