Support Windows 7 RTM Host

Co-Authored-By: gailium119 <77530553+gailium119@users.noreply.github.com>

util/cutils.c

@@ -44,7 +44,126 @@
 #endif
 
 #ifdef G_OS_WIN32
-#include <pathcch.h>
+#include "pathcch2.h"
+#include <Windows.h>
+
+static BOOL is_prefixed_volume(const WCHAR* string)
+{
+    const WCHAR* guid;
+    INT i = 0;
+
+    if (wcsnicmp(string, L"\\\\?\\Volume", 10)) return FALSE;
+
+    guid = string + 10;
+
+    while (i <= 37)
+    {
+        switch (i)
+        {
+        case 0:
+            if (guid[i] != '{') return FALSE;
+            break;
+        case 9:
+        case 14:
+        case 19:
+        case 24:
+            if (guid[i] != '-') return FALSE;
+            break;
+        case 37:
+            if (guid[i] != '}') return FALSE;
+            break;
+        default:
+            if (!isxdigit(guid[i])) return FALSE;
+            break;
+        }
+        i++;
+    }
+
+    return TRUE;
+}
+
+static BOOL is_prefixed_unc(const WCHAR* string)
+{
+    return !wcsnicmp(string, L"\\\\?\\UNC\\", 8);
+}
+
+static BOOL is_drive_spec(const WCHAR* str)
+{
+    return isalpha(str[0]) && str[1] == ':';
+}
+
+static BOOL is_prefixed_disk(const WCHAR* string)
+{
+    return !wcsncmp(string, L"\\\\?\\", 4) && is_drive_spec(string + 4);
+}
+/* Find the last character of the root in a path, if there is one, without any segments */
+static const WCHAR* get_root_end(const WCHAR* path)
+{
+    /* Find path root */
+    if (is_prefixed_volume(path))
+        return path[48] == '\\' ? path + 48 : path + 47;
+    else if (is_prefixed_unc(path))
+        return path + 7;
+    else if (is_prefixed_disk(path))
+        return path[6] == '\\' ? path + 6 : path + 5;
+    /* \\ */
+    else if (path[0] == '\\' && path[1] == '\\')
+        return path + 1;
+    /* \ */
+    else if (path[0] == '\\')
+        return path;
+    /* X:\ */
+    else if (is_drive_spec(path))
+        return path[2] == '\\' ? path + 2 : path + 1;
+    else
+        return NULL;
+}
+
+/* Get the next character beyond end of the segment.
+   Return TRUE if the last segment ends with a backslash */
+static BOOL get_next_segment(const WCHAR* next, const WCHAR** next_segment)
+{
+    while (*next && *next != '\\') next++;
+    if (*next == '\\')
+    {
+        *next_segment = next + 1;
+        return TRUE;
+    }
+    else
+    {
+        *next_segment = next;
+        return FALSE;
+    }
+}
+
+HRESULT WINAPI PathCchSkipRoot2(const WCHAR* path, const WCHAR** root_end)
+{
+
+    if (!path || !path[0] || !root_end
+        || (!wcsnicmp(path, L"\\\\?", 3) && !is_prefixed_volume(path) && !is_prefixed_unc(path)
+            && !is_prefixed_disk(path)))
+        return E_INVALIDARG;
+
+    *root_end = get_root_end(path);
+    if (*root_end)
+    {
+        (*root_end)++;
+        if (is_prefixed_unc(path))
+        {
+            get_next_segment(*root_end, root_end);
+            get_next_segment(*root_end, root_end);
+        }
+        else if (path[0] == '\\' && path[1] == '\\' && path[2] != '?')
+        {
+            /* Skip share server */
+            get_next_segment(*root_end, root_end);
+            /* If mount point is empty, don't skip over mount point */
+            if (**root_end != '\\') get_next_segment(*root_end, root_end);
+        }
+    }
+
+    return *root_end ? S_OK : E_INVALIDARG;
+}
 #include <wchar.h>
 #endif
 
@@ -1169,7 +1288,7 @@ char *get_relocated_path(const char *dir)
         mbsrtowcs(wdir, &src, size, &(mbstate_t){0});
 
         PCWSTR wdir_skipped_root;
-        if (PathCchSkipRoot(wdir, &wdir_skipped_root) == S_OK) {
+        if (PathCchSkipRoot2(wdir, &wdir_skipped_root) == S_OK) {
             size = wcsrtombs(NULL, &wdir_skipped_root, 0, &(mbstate_t){0});
             char *cursor = result->str + result->len;
             g_string_set_size(result, result->len + size);

util/meson.build

@@ -25,7 +25,6 @@ else
   util_ss.add(files('event_notifier-win32.c'))
   util_ss.add(files('oslib-win32.c'))
   util_ss.add(files('qemu-thread-win32.c'))
-  util_ss.add(winmm, pathcch)
 endif
 util_ss.add(when: linux_io_uring, if_true: files('fdmon-io_uring.c'))
 if glib_has_gslice

util/pathcch2.h

@@ -0,0 +1 @@
+HRESULT WINAPI PathCchSkipRoot2(const WCHAR* path, const WCHAR** root_end);