From 053d9715076860b393956ca3c1451bcd578bf3f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Sun, 5 May 2024 18:50:38 +0200
Subject: [PATCH] misc/path_utils: normalize win32 paths

---
 meson.build       |  5 +++++
 misc/path_utils.c | 34 +++++++++++++++++++++++++++++++++-
 test/meson.build  |  3 +++
 test/paths.c      | 23 ++++++++++++++++++++++-
 4 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index b33eef90ea..be0b5c89cd 100644
--- a/meson.build
+++ b/meson.build
@@ -495,6 +495,11 @@ endif
 
 features += {'win32-desktop': win32 and not uwp.found()}
 if features['win32-desktop']
+    pathcch = cc.find_library('pathcch', required: false)
+    features += {'pathcch': pathcch.found()}
+    if features['pathcch']
+        dependencies += pathcch
+    endif
     win32_desktop_libs = [cc.find_library('avrt'),
                           cc.find_library('dwmapi'),
                           cc.find_library('gdi32'),
diff --git a/misc/path_utils.c b/misc/path_utils.c
index 7fbd1084b8..a1484a9046 100644
--- a/misc/path_utils.c
+++ b/misc/path_utils.c
@@ -34,6 +34,11 @@
 #include "misc/ctype.h"
 #include "misc/path_utils.h"
 
+#if defined(HAVE_PATHCCH) && HAVE_PATHCCH
+#include <windows.h>
+#include <pathcch.h>
+#endif
+
 char *mp_basename(const char *path)
 {
     char *s;
@@ -164,7 +169,34 @@ char *mp_normalize_path(void *talloc_ctx, const char *path)
         path = mp_path_join(talloc_ctx, cwd, path);
     }
 
-#if HAVE_DOS_PATHS
+#if defined(HAVE_PATHCCH) && HAVE_PATHCCH
+    wchar_t *pathw = mp_from_utf8(NULL, path);
+    wchar_t *read = pathw, *write = pathw;
+    wchar_t prev = '\0';
+    // preserve leading double backslashes
+    if (read[0] == '\\' && read[1] == '\\') {
+        prev = '\\';
+        write += 2;
+        read += 2;
+    }
+    wchar_t curr;
+    while ((curr = *read)) {
+        if (curr == '/')
+            curr = '\\';
+        if (curr != '\\' || prev != '\\')
+            *write++ = curr;
+        prev = curr;
+        read++;
+    }
+    *write = '\0';
+    size_t max_size = wcslen(pathw) + 1;
+    wchar_t *pathc = talloc_array(NULL, wchar_t, max_size);
+    HRESULT hr = PathCchCanonicalizeEx(pathc, max_size, pathw, PATHCCH_ALLOW_LONG_PATHS);
+    char *ret = SUCCEEDED(hr) ? mp_to_utf8(talloc_ctx, pathc) : talloc_strdup(talloc_ctx, path);
+    talloc_free(pathw);
+    talloc_free(pathc);
+    return ret;
+#elif HAVE_DOS_PATHS
     return talloc_strdup(talloc_ctx, path);
 #else
     char *result = talloc_strdup(talloc_ctx, "");
diff --git a/test/meson.build b/test/meson.build
index e34d72ca02..f77ddf3092 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -53,6 +53,9 @@ endif
 if features['win32-desktop']
     test_utils_deps += cc.find_library('imm32')
     test_utils_deps += cc.find_library('ntdll')
+    if features['pathcch']
+        test_utils_deps += cc.find_library('pathcch')
+    endif
 endif
 test_utils_objects = libmpv.extract_objects(test_utils_files)
 test_utils = static_library('test-utils', 'test_utils.c', include_directories: incdir,
diff --git a/test/paths.c b/test/paths.c
index e18c9dfb1c..13b3b26779 100644
--- a/test/paths.c
+++ b/test/paths.c
@@ -81,15 +81,36 @@ int main(void)
 #endif
 
     TEST_NORMALIZE("https://foo", "https://foo");
+#if !HAVE_DOS_PATHS
     TEST_NORMALIZE("/foo", "/foo");
+#endif
 
     void *ctx = talloc_new(NULL);
     bstr dst = bstr0(mp_getcwd(ctx));
     bstr_xappend(ctx, &dst, bstr0("/foo"));
+#if HAVE_DOS_PATHS
+    char *p = dst.start;
+    while (*p) {
+        *p = *p == '/' ? '\\' : *p;
+        p++;
+    }
+#endif
     TEST_NORMALIZE(dst.start, "foo");
     talloc_free(ctx);
 
-#if (!HAVE_DOS_PATHS)
+#if HAVE_DOS_PATHS
+    TEST_NORMALIZE("C:\\foo\\baz", "C:/foo/bar/../baz");
+    TEST_NORMALIZE("C:\\", "C:/foo/../..");
+    TEST_NORMALIZE("C:\\foo\\baz", "C:/foo/bar/./../baz");
+    TEST_NORMALIZE("C:\\foo\\bar\\baz", "C:/foo//bar/./baz");
+    TEST_NORMALIZE("C:\\foo\\bar\\baz", "C:/foo\\./bar\\/baz");
+    TEST_NORMALIZE("C:\\file.mkv", "\\\\?\\C:\\folder\\..\\file.mkv");
+    TEST_NORMALIZE("C:\\dir", "\\\\?\\C:\\dir\\subdir\\..\\.");
+    TEST_NORMALIZE("D:\\newfile.txt", "\\\\?\\D:\\\\new\\subdir\\..\\..\\newfile.txt");
+    TEST_NORMALIZE("\\\\server\\share\\path", "\\\\?\\UNC/server/share/path/.");
+    TEST_NORMALIZE("C:\\", "C:/.");
+    TEST_NORMALIZE("C:\\", "C:/../");
+#else
     TEST_NORMALIZE("/foo/bar", "/foo//bar");
     TEST_NORMALIZE("/foo/bar", "/foo///bar");
     TEST_NORMALIZE("/foo/bar", "/foo/bar/");