From 94a8e87c714871dc80478e6636d8fc178f9abd46 Mon Sep 17 00:00:00 2001
From: gabime <gmelman1@gmail.com>
Date: Mon, 29 Apr 2024 19:46:59 +0300
Subject: [PATCH] Fix #3079

---
 include/spdlog/details/os-inl.h |  9 +++++
 tests/test_create_dir.cpp       | 62 +++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index 0993c195..26cee740 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -534,6 +534,15 @@ SPDLOG_INLINE bool create_dir(const filename_t &path) {
         }
 
         auto subdir = path.substr(0, token_pos);
+#ifdef _WIN32
+        // if subdir is just a drive letter, add a slash e.g. "c:"=>"c:\", 
+        // otherwise path_exists(subdir) returns false (issue #3079)
+        const bool is_drive = subdir.length() == 2 && subdir[1] == ':';
+        if (is_drive) {
+            subdir += '\\';
+            token_pos++;
+        }
+#endif
 
         if (!subdir.empty() && !path_exists(subdir) && !mkdir_(subdir)) {
             return false;  // return error if failed creating dir
diff --git a/tests/test_create_dir.cpp b/tests/test_create_dir.cpp
index f88825b0..3dbcf29c 100644
--- a/tests/test_create_dir.cpp
+++ b/tests/test_create_dir.cpp
@@ -81,3 +81,65 @@ TEST_CASE("dir_name", "[create_dir]") {
     REQUIRE(dir_name(SPDLOG_FILENAME_T("../file.txt")) == SPDLOG_FILENAME_T(".."));
     REQUIRE(dir_name(SPDLOG_FILENAME_T("./file.txt")) == SPDLOG_FILENAME_T("."));
 }
+
+#ifdef _WIN32
+
+//
+// test windows cases when drive letter is given e.g. C:\\some-folder\
+//
+#include <windows.h>
+#include <fileapi.h>
+
+std::string get_full_path(const std::string &relative_folder_path) {
+    char full_path[MAX_PATH];
+
+    DWORD result = ::GetFullPathNameA(relative_folder_path.c_str(), MAX_PATH, full_path, nullptr);
+    // Return an empty string if failed to get full path
+    return result > 0 && result < MAX_PATH ? std::string(full_path) : std::string();    
+}
+
+std::wstring get_full_path(const std::wstring &relative_folder_path) {
+    wchar_t full_path[MAX_PATH];
+    DWORD result = ::GetFullPathNameW(relative_folder_path.c_str(), MAX_PATH, full_path, nullptr);    
+    return result > 0 && result < MAX_PATH ? std::wstring(full_path) : std::wstring();
+}
+
+spdlog::filename_t::value_type find_non_existing_drive() {
+    for (char drive = 'A'; drive <= 'Z'; ++drive) {
+        std::string root_path = std::string(1, drive) + ":\\";
+        UINT drive_type = GetDriveTypeA(root_path.c_str());
+        if (drive_type == DRIVE_NO_ROOT_DIR) {
+            return static_cast <spdlog::filename_t::value_type>(drive);
+        }
+    }
+    return '\0';  // No available drive found
+}
+
+TEST_CASE("create_abs_path1", "[create_dir]") {
+    prepare_logdir();    
+    auto abs_path = get_full_path(SPDLOG_FILENAME_T("test_logs\\logdir1"));
+    REQUIRE(!abs_path.empty());            
+    REQUIRE(create_dir(abs_path) == true);
+}
+
+TEST_CASE("create_abs_path2", "[create_dir]") {
+    prepare_logdir();
+    auto abs_path = get_full_path(SPDLOG_FILENAME_T("test_logs/logdir2"));
+    REQUIRE(!abs_path.empty());
+    REQUIRE(create_dir(abs_path) == true);        
+}
+
+TEST_CASE("non_existing_drive", "[create_dir]") {    
+    prepare_logdir();        
+    spdlog::filename_t path;
+    
+    auto non_existing_drive = find_non_existing_drive();
+    path += non_existing_drive ;
+    path += SPDLOG_FILENAME_T(":\\");    
+    REQUIRE(create_dir(path) == false);    
+    path += SPDLOG_FILENAME_T("subdir");
+    REQUIRE(create_dir(path) == false);
+            
+}
+//#endif  // SPDLOG_WCHAR_FILENAMES
+#endif  // _WIN32