source/blender/blenlib/BLI_fileops.h

@@ -142,6 +142,18 @@ double BLI_dir_free_space(const char *dir) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(
  */
 char *BLI_current_working_dir(char *dir, size_t maxncpy) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 eFileAttributes BLI_file_attributes(const char *path);
+/**
+ * Changes the current working directory to the provided path.
+ *
+ * Usage of this function is strongly discouraged as it is not thread safe. It will likely cause
+ * issues if there is an operation on another thread that does not expect the current working
+ * directory to change. This has been added to support USDZ export, which has a problematic
+ * "feature" described in this task https://developer.blender.org/D15623. It will be removed if it
+ * is possible to resolve that issue upstream in the USD library.
+ *
+ * \return true on success, false otherwise.
+ */
+bool BLI_change_working_dir(const char *dir);
 
 /** \} */
 
@@ -313,6 +325,8 @@ void BLI_file_free_lines(struct LinkNode *lines);
  * Giving a path without leading `~` is not an error.
  */
 const char *BLI_expand_tilde(const char *path_with_tilde);
+const char *BLI_apple_getcwd(const size_t max_length);
+int BLI_apple_chdir(const char *dir);
 #endif
 /* This weirdo pops up in two places. */
 #if !defined(WIN32)

source/blender/blenlib/intern/storage.c

@@ -54,8 +54,33 @@
 #include "BLI_linklist.h"
 #include "BLI_path_util.h"
 #include "BLI_string.h"
+#include "BLI_threads.h"
 #include "BLI_utildefines.h"
 
+bool BLI_change_working_dir(const char *dir)
+{
+  BLI_assert(BLI_thread_is_main());
+
+  if (!BLI_is_dir(dir)) {
+    return false;
+  }
+#if defined(WIN32)
+  wchar_t wdir[FILE_MAX];
+  if (conv_utf_8_to_16(dir, wdir, ARRAY_SIZE(wdir)) != 0) {
+    return false;
+  }
+  return _wchdir(wdir) == 0;
+#elif defined(__APPLE__)
+  return BLI_apple_chdir(dir) == 0;
+#else
+  int result = chdir(dir);
+  if (result == 0) {
+    BLI_setenv("PWD", dir);
+  }
+  return result == 0;
+#endif
+}
+
 char *BLI_current_working_dir(char *dir, const size_t maxncpy)
 {
 #if defined(WIN32)
@@ -66,6 +91,9 @@ char *BLI_current_working_dir(char *dir, const size_t maxncpy)
     }
   }
   return NULL;
+#elif defined(__APPLE__)
+  BLI_strncpy(dir, BLI_apple_getcwd(maxncpy), maxncpy);
+  return dir;
 #else
   const char *pwd = BLI_getenv("PWD");
   if (pwd) {

source/blender/blenlib/intern/storage_apple.mm

@@ -185,3 +185,27 @@ const char *BLI_expand_tilde(const char *path_with_tilde)
   }
   return path_expanded;
 }
+
+
+const char *BLI_apple_getcwd(const size_t max_length) {
+  static char path_expanded[PATH_MAX];
+  @autoreleasepool {
+    NSString *path = [[NSFileManager defaultManager] currentDirectoryPath];
+    const size_t length = max_length > PATH_MAX ? PATH_MAX : max_length;
+    [path getCString:path_expanded maxLength: length encoding:NSUTF8StringEncoding];
+    return path_expanded;
+  }
+}
+
+
+int BLI_apple_chdir(const char* dir) {
+  @autoreleasepool {
+    NSString* path = [[NSString alloc] initWithUTF8String: dir];
+    if ([[NSFileManager defaultManager] changeCurrentDirectoryPath: path] == YES) {
+      return 0;
+    }
+    else {
+      return -1;
+    }
+  }
+}

source/blender/blenlib/tests/BLI_fileops_test.cc

@@ -1,9 +1,12 @@
 /* SPDX-License-Identifier: Apache-2.0 */
 
-#include "BLI_fileops.hh"
-
 #include "testing/testing.h"
 
+#include "BLI_fileops.hh"
+#include "BLI_path_util.h"
+#include "BLI_string.h"
+#include "BLI_threads.h"
+
 namespace blender::tests {
 
 TEST(fileops, fstream_open_string_filename)
@@ -37,4 +40,39 @@ TEST(fileops, fstream_open_charptr_filename)
   /* Reading the file not tested here. That's deferred to `std::fstream` anyway. */
 }
 
+TEST(fileops, change_working_directory)
+{
+  BLI_threadapi_init();
+
+  char original_wd[FILE_MAX];
+  BLI_current_working_dir(original_wd, FILE_MAX);
+
+  const std::string test_temp_dir = blender::tests::flags_test_asset_dir() + "/" +
+                                    "fileops_test_temp_новый";
+
+  if (BLI_exists(test_temp_dir.c_str())) {
+    BLI_delete(test_temp_dir.c_str(), true, false);
+  }
+
+  bool result = BLI_change_working_dir(test_temp_dir.c_str());
+  ASSERT_FALSE(result);
+
+  BLI_dir_create_recursive(test_temp_dir.c_str());
+
+  result = BLI_change_working_dir(test_temp_dir.c_str());
+  ASSERT_TRUE(result);
+
+  char cwd[FILE_MAX];
+  BLI_current_working_dir(cwd, FILE_MAX);
+
+  ASSERT_TRUE(BLI_path_cmp_normalized(cwd, test_temp_dir.c_str()) == 0);
+
+  result = BLI_change_working_dir(original_wd);
+  ASSERT_TRUE(result);
+
+  BLI_delete(test_temp_dir.c_str(), true, false);
+
+  BLI_threadapi_exit();
+}
+
 }  // namespace blender::tests