win32: add (some) long path supportlong_paths

Use the longPathAware manifest entry to handle path lengths above
260.  This requires the LongPathsEnabled registry key to be set
at run-time.

Modify (some) WIN32 API calls to use the wide-character variant.

These features are controlled by the build-time configuration
option FEATURE_LONG_PATHS, which is not enabled by default.

1 files changed, 23 insertions, 2 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index 122337d19..0c28d87fe 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -396,6 +396,9 @@ static inline mode_t file_attr_to_st_mode(DWORD attr)
 
 static int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata)
 {
+#if ENABLE_FEATURE_LONG_PATHS
+        wchar_t wpath[32768];
+#endif
         char *want_dir;
         int dev = get_dev_type(fname);
 
@@ -412,7 +415,18 @@ static int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata)
         }
 
         want_dir = last_char_is_dir_sep(fname);
-        if (GetFileAttributesExA(fname, GetFileExInfoStandard, fdata)) {
+
+#if !ENABLE_FEATURE_LONG_PATHS
+        if (GetFileAttributesExA(fname, GetFileExInfoStandard, fdata))
+#else
+        /* Convert to wide string for long path support.  CP_ACP is CP_UTF8
+         * when the UTF-8 manifest is active, else the system ANSI code page. */
+        if (MultiByteToWideChar(CP_ACP, 0, fname, -1, wpath, 32768) == 0)
+                return EINVAL;
+
+        if (GetFileAttributesExW(wpath, GetFileExInfoStandard, fdata))
+#endif
+        {
                 if (!(fdata->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) && want_dir)
                         return ENOTDIR;
                 fdata->dwFileAttributes &= ~FILE_ATTRIBUTE_DEVICE;
@@ -421,9 +435,16 @@ static int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata)
 
         if (GetLastError() == ERROR_SHARING_VIOLATION) {
                 HANDLE hnd;
+#if !ENABLE_FEATURE_LONG_PATHS
                 WIN32_FIND_DATA fd;
 
-                if ((hnd=FindFirstFile(fname, &fd)) != INVALID_HANDLE_VALUE) {
+                if ((hnd=FindFirstFile(fname, &fd)) != INVALID_HANDLE_VALUE)
+#else
+                WIN32_FIND_DATAW fd;
+
+                if ((hnd=FindFirstFileW(wpath, &fd)) != INVALID_HANDLE_VALUE)
+#endif
+                {
                         fdata->dwFileAttributes =
                                         fd.dwFileAttributes & ~FILE_ATTRIBUTE_DEVICE;
                         fdata->ftCreationTime = fd.ftCreationTime;