[vcpkg] Fix the case of current_path() before use on Windows. (#13537)

* Fix the case of current_path() before use on Windows.

This is a better solution than that I tried in https://github.com/microsoft/vcpkg/pull/13144 -- rather than trying to cannoicalize the path completely, which would destroy symlinks etc; this form  calls FindFirstFile on each path element to get the real case from the filesystem.

Fixes #13105.

(Note the wrong case in the CWD in the prompt, but the correct case in all the output:)

PS C:\DeV\vcPKG> .\vcpkg.exe install curl
Computing installation plan...
The following packages will be built and installed:
    curl[core,non-http,schannel,ssl,sspi,winssl]:x86-windows
  * zlib[core]:x86-windows
Additional packages (*) will be modified to complete this operation.
Detecting compiler hash for triplet x86-windows...
Starting package 1/2: zlib:x86-windows
Building package zlib[core]:x86-windows...
Using cached binary package: C:\Users\billy\AppData\Local\vcpkg/archives\c6\c61dd1bcc23348934c55f4ced77f1e4b0f353394.zipBuilding package zlib[core]:x86-windows... done
Installing package zlib[core]:x86-windows...
Installing package zlib[core]:x86-windows... done
Elapsed time for package zlib:x86-windows: 62.26 ms
Starting package 2/2: curl:x86-windows
Building package curl[core,non-http,schannel,ssl,sspi,winssl]:x86-windows...
Could not locate cached archive: C:\Users\billy\AppData\Local\vcpkg/archives\9f\9fa16d473c9539e9ea7ab3922eff46618f3a4c4b.zip
-- Downloading https://github.com/curl/curl/archive/9d954e49bce3706a9a2efb119ecd05767f0f2a9e.tar.gz...
-- Extracting source C:/Dev/vcpkg/downloads/curl-curl-9d954e49bce3706a9a2efb119ecd05767f0f2a9e.tar.gz
-- Applying patch 0002_fix_uwp.patch
-- Applying patch 0004_nghttp2_staticlib.patch
-- Applying patch 0005_remove_imp_suffix.patch
-- Applying patch 0006_fix_tool_depends.patch
-- Applying patch 0007_disable_tool_export_curl_target.patch
-- Applying patch 0009_fix_openssl_config.patch
-- Applying patch 0010_fix_othertests_cmake.patch
-- Applying patch 0011_fix_static_build.patch
-- Using source at C:/Dev/vcpkg/buildtrees/curl/src/767f0f2a9e-91d24adee1.clean
-- Configuring x86-windows
-- Building x86-windows-dbg
-- Building x86-windows-rel
-- Installing: C:/Dev/vcpkg/packages/curl_x86-windows/share/curl/curl-config
-- Installing: C:/Dev/vcpkg/packages/curl_x86-windows/share/curl/vcpkg-cmake-wrapper.cmake
-- Installing: C:/Dev/vcpkg/packages/curl_x86-windows/share/curl/copyright
-- Performing post-build validation
-- Performing post-build validation done
Stored binary cache: C:\Users\billy\AppData\Local\vcpkg/archives\9f\9fa16d473c9539e9ea7ab3922eff46618f3a4c4b.zip
Building package curl[core,non-http,schannel,ssl,sspi,winssl]:x86-windows... done
Installing package curl[core,non-http,schannel,ssl,sspi,winssl]:x86-windows...
Installing package curl[core,non-http,schannel,ssl,sspi,winssl]:x86-windows... done
Elapsed time for package curl:x86-windows: 1.299 min

Total elapsed time: 1.33 min

The package curl:x86-windows provides CMake targets:

    find_package(CURL CONFIG REQUIRED)
    target_link_libraries(main PRIVATE CURL::libcurl)

PS C:\DeV\vcPKG>

* Fix *nix builds.

* PR feedback.

* Update toolsrc/src/vcpkg/base/files.cpp

Co-authored-by: ras0219 <533828+ras0219@users.noreply.github.com>

4 files changed, 246 insertions, 18 deletions

diff --git a/toolsrc/include/vcpkg/base/files.h b/toolsrc/include/vcpkg/base/files.h
index 08bbe7906..71e386a5c 100644
--- a/toolsrc/include/vcpkg/base/files.h
+++ b/toolsrc/include/vcpkg/base/files.h
@@ -237,4 +237,8 @@ namespace vcpkg::Files
     /// Performs "lhs / rhs" according to the C++17 Filesystem Library Specification.
     /// This function exists as a workaround for TS implementations.
     fs::path combine(const fs::path& lhs, const fs::path& rhs);
+
+#if defined(_WIN32)
+    fs::path win32_fix_path_case(const fs::path& source);
+#endif // _WIN32
 }
diff --git a/toolsrc/src/vcpkg-test/files.cpp b/toolsrc/src/vcpkg-test/files.cpp
index a8c7c2ba2..429a4ba15 100644
--- a/toolsrc/src/vcpkg-test/files.cpp
+++ b/toolsrc/src/vcpkg-test/files.cpp
@@ -194,6 +194,62 @@ TEST_CASE ("remove all", "[files]")
     CHECK_EC_ON_FILE(temp_dir, ec);
 }
 
+#if defined(_WIN32)
+TEST_CASE ("win32_fix_path_case", "[files]")
+{
+    using vcpkg::Files::win32_fix_path_case;
+
+    // This test assumes that the Windows directory is C:\Windows
+
+    CHECK(win32_fix_path_case(L"") == L"");
+
+    CHECK(win32_fix_path_case(L"C:") == L"C:");
+    CHECK(win32_fix_path_case(L"c:") == L"C:");
+    CHECK(win32_fix_path_case(L"C:/") == L"C:\\");
+    CHECK(win32_fix_path_case(L"C:\\") == L"C:\\");
+    CHECK(win32_fix_path_case(L"c:\\") == L"C:\\");
+    CHECK(win32_fix_path_case(L"C:\\WiNdOws") == L"C:\\Windows");
+    CHECK(win32_fix_path_case(L"c:\\WiNdOws\\") == L"C:\\Windows\\");
+    CHECK(win32_fix_path_case(L"C://///////WiNdOws") == L"C:\\Windows");
+    CHECK(win32_fix_path_case(L"c:\\/\\/WiNdOws\\/") == L"C:\\Windows\\");
+
+    auto& fs = vcpkg::Files::get_real_filesystem();
+    auto original_cwd = fs.current_path(VCPKG_LINE_INFO);
+    fs.current_path(L"C:\\", VCPKG_LINE_INFO);
+    CHECK(win32_fix_path_case(L"\\") == L"\\");
+    CHECK(win32_fix_path_case(L"\\/\\WiNdOws") == L"\\Windows");
+    CHECK(win32_fix_path_case(L"\\WiNdOws") == L"\\Windows");
+    CHECK(win32_fix_path_case(L"\\WiNdOws") == L"\\Windows");
+    CHECK(win32_fix_path_case(L"c:WiNdOws") == L"C:Windows");
+    CHECK(win32_fix_path_case(L"c:WiNdOws/system32") == L"C:Windows\\System32");
+    fs.current_path(original_cwd, VCPKG_LINE_INFO);
+
+    fs.create_directories("SuB/Dir/Ectory", VCPKG_LINE_INFO);
+    CHECK(win32_fix_path_case(L"sub") == L"SuB");
+    CHECK(win32_fix_path_case(L"SUB") == L"SuB");
+    CHECK(win32_fix_path_case(L"sub/") == L"SuB\\");
+    CHECK(win32_fix_path_case(L"sub/dir") == L"SuB\\Dir");
+    CHECK(win32_fix_path_case(L"sub/dir/") == L"SuB\\Dir\\");
+    CHECK(win32_fix_path_case(L"sub/dir/ectory") == L"SuB\\Dir\\Ectory");
+    CHECK(win32_fix_path_case(L"sub/dir/ectory/") == L"SuB\\Dir\\Ectory\\");
+    fs.remove_all("SuB", VCPKG_LINE_INFO);
+
+    CHECK(win32_fix_path_case(L"//nonexistent_server\\nonexistent_share\\") ==
+          L"\\\\nonexistent_server\\nonexistent_share\\");
+    CHECK(win32_fix_path_case(L"\\\\nonexistent_server\\nonexistent_share\\") ==
+          L"\\\\nonexistent_server\\nonexistent_share\\");
+    CHECK(win32_fix_path_case(L"\\\\nonexistent_server\\nonexistent_share") ==
+          L"\\\\nonexistent_server\\nonexistent_share");
+
+    CHECK(win32_fix_path_case(L"///three_slashes_not_a_server\\subdir\\") == L"\\three_slashes_not_a_server\\subdir\\");
+
+    CHECK(win32_fix_path_case(L"\\??\\c:\\WiNdOws") == L"\\??\\c:\\WiNdOws");
+    CHECK(win32_fix_path_case(L"\\\\?\\c:\\WiNdOws") == L"\\\\?\\c:\\WiNdOws");
+    CHECK(win32_fix_path_case(L"\\\\.\\c:\\WiNdOws") == L"\\\\.\\c:\\WiNdOws");
+    CHECK(win32_fix_path_case(L"c:\\/\\/Nonexistent\\/path/here") == L"C:\\Nonexistent\\path\\here");
+}
+#endif // _WIN32
+
 #if defined(CATCH_CONFIG_ENABLE_BENCHMARKING)
 TEST_CASE ("remove all -- benchmarks", "[files][!benchmark]")
 {
diff --git a/toolsrc/src/vcpkg/base/files.cpp b/toolsrc/src/vcpkg/base/files.cpp
index 51c6c9c76..916c26bda 100644
--- a/toolsrc/src/vcpkg/base/files.cpp
+++ b/toolsrc/src/vcpkg/base/files.cpp
@@ -5,12 +5,14 @@
 #include <vcpkg/base/system.process.h>
 #include <vcpkg/base/util.h>
 
-#if !defined(_WIN32)
+#if defined(_WIN32)
+#include <vcpkg/base/system_headers.h>
+#else // ^^^ _WIN32 // !_WIN32 vvv
 #include <fcntl.h>
 
 #include <sys/file.h>
 #include <sys/stat.h>
-#endif
+#endif // _WIN32
 
 #if defined(__linux__)
 #include <sys/sendfile.h>
@@ -18,6 +20,78 @@
 #include <copyfile.h>
 #endif // ^^^ defined(__APPLE__)
 
+#include <algorithm>
+#include <string>
+
+#if defined(_WIN32)
+namespace
+{
+    struct IsSlash
+    {
+        bool operator()(const wchar_t c) const noexcept { return c == L'/' || c == L'\\'; }
+    };
+
+    constexpr IsSlash is_slash;
+
+    template<size_t N>
+    bool wide_starts_with(const std::wstring& haystack, const wchar_t (&needle)[N]) noexcept
+    {
+        const size_t without_null = N - 1;
+        return haystack.size() >= without_null && std::equal(needle, needle + without_null, haystack.begin());
+    }
+
+    bool starts_with_drive_letter(std::wstring::const_iterator first, const std::wstring::const_iterator last) noexcept
+    {
+        if (last - first < 2)
+        {
+            return false;
+        }
+
+        if (!(first[0] >= L'a' && first[0] <= L'z') && !(first[0] >= L'A' && first[0] <= L'Z'))
+        {
+            return false;
+        }
+
+        if (first[1] != L':')
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    struct FindFirstOp
+    {
+        HANDLE h_find = INVALID_HANDLE_VALUE;
+        WIN32_FIND_DATAW find_data;
+
+        unsigned long find_first(const wchar_t* const path) noexcept
+        {
+            assert(h_find == INVALID_HANDLE_VALUE);
+            h_find = FindFirstFileW(path, &find_data);
+            if (h_find == INVALID_HANDLE_VALUE)
+            {
+                return GetLastError();
+            }
+
+            return ERROR_SUCCESS;
+        }
+
+        FindFirstOp() = default;
+        FindFirstOp(const FindFirstOp&) = delete;
+        FindFirstOp& operator=(const FindFirstOp&) = delete;
+
+        ~FindFirstOp()
+        {
+            if (h_find != INVALID_HANDLE_VALUE)
+            {
+                (void)FindClose(h_find);
+            }
+        }
+    };
+} // unnamed namespace
+#endif // _WIN32
+
 fs::path fs::u8path(vcpkg::StringView s)
 {
 #if defined(_WIN32)
@@ -1197,4 +1271,106 @@ namespace vcpkg::Files
 #endif // ^^^ windows
 #endif // ^^^ std::experimental::filesystem
     }
+
+#ifdef _WIN32
+    fs::path win32_fix_path_case(const fs::path& source)
+    {
+        const std::wstring& native = source.native();
+        if (native.empty())
+        {
+            return fs::path{};
+        }
+
+        if (wide_starts_with(native, L"\\\\?\\") || wide_starts_with(native, L"\\??\\") ||
+            wide_starts_with(native, L"\\\\.\\"))
+        {
+            // no support to attempt to fix paths in the NT, \\GLOBAL??, or device namespaces at this time
+            return source;
+        }
+
+        const auto last = native.end();
+        auto first = native.begin();
+        auto is_wildcard = [](wchar_t c) { return c == L'?' || c == L'*'; };
+        if (std::any_of(first, last, is_wildcard))
+        {
+            Checks::exit_with_message(
+                VCPKG_LINE_INFO, "Attempt to fix case of a path containing wildcards: %s", fs::u8string(source));
+        }
+
+        std::wstring in_progress;
+        in_progress.reserve(native.size());
+        if (last - first >= 3 && is_slash(first[0]) && is_slash(first[1]) && !is_slash(first[2]))
+        {
+            // path with UNC prefix \\server\share; this will be rejected by FindFirstFile so we skip over that
+            in_progress.push_back(L'\\');
+            in_progress.push_back(L'\\');
+            first += 2;
+            auto next_slash = std::find_if(first, last, is_slash);
+            in_progress.append(first, next_slash);
+            in_progress.push_back(L'\\');
+            first = std::find_if_not(next_slash, last, is_slash);
+            next_slash = std::find_if(first, last, is_slash);
+            in_progress.append(first, next_slash);
+            first = std::find_if_not(next_slash, last, is_slash);
+            if (first != next_slash)
+            {
+                in_progress.push_back(L'\\');
+            }
+        }
+        else if (last - first >= 1 && is_slash(first[0]))
+        {
+            // root relative path
+            in_progress.push_back(L'\\');
+            first = std::find_if_not(first, last, is_slash);
+        }
+        else if (starts_with_drive_letter(first, last))
+        {
+            // path with drive letter root
+            auto letter = first[0];
+            if (letter >= L'a' && letter <= L'z')
+            {
+                letter = letter - L'a' + L'A';
+            }
+
+            in_progress.push_back(letter);
+            in_progress.push_back(L':');
+            first += 2;
+            if (first != last && is_slash(*first))
+            {
+                // absolute path
+                in_progress.push_back(L'\\');
+                first = std::find_if_not(first, last, is_slash);
+            }
+        }
+
+        assert(!fs::path(first, last).has_root_path());
+
+        while (first != last)
+        {
+            auto next_slash = std::find_if(first, last, is_slash);
+            auto original_size = in_progress.size();
+            in_progress.append(first, next_slash);
+            FindFirstOp this_find;
+            unsigned long last_error = this_find.find_first(in_progress.c_str());
+            if (last_error == ERROR_SUCCESS)
+            {
+                in_progress.resize(original_size);
+                in_progress.append(this_find.find_data.cFileName);
+            }
+            else
+            {
+                // we might not have access to this intermediate part of the path;
+                // just guess that the case of that element is correct and move on
+            }
+
+            first = std::find_if_not(next_slash, last, is_slash);
+            if (first != next_slash)
+            {
+                in_progress.push_back(L'\\');
+            }
+        }
+
+        return fs::path(std::move(in_progress));
+    }
+#endif // _WIN32
 }
diff --git a/toolsrc/src/vcpkg/vcpkgpaths.cpp b/toolsrc/src/vcpkg/vcpkgpaths.cpp
index 9f4ffce6b..60403edbd 100644
--- a/toolsrc/src/vcpkg/vcpkgpaths.cpp
+++ b/toolsrc/src/vcpkg/vcpkgpaths.cpp
@@ -62,24 +62,13 @@ namespace
         Files::Filesystem& filesystem, const fs::path& root, std::string* option, StringLiteral name, LineInfo li)
     {
         auto result = process_output_directory_impl(filesystem, root, option, name, li);
+#if defined(_WIN32)
+        result = vcpkg::Files::win32_fix_path_case(result);
+#endif // _WIN32
         Debug::print("Using ", name, "-root: ", fs::u8string(result), '\n');
         return result;
     }
 
-    void uppercase_win32_drive_letter(fs::path& path)
-    {
-#if defined(_WIN32)
-        const auto& nativePath = path.native();
-        if (nativePath.size() > 2 && (nativePath[0] >= L'a' && nativePath[0] <= L'z') && nativePath[1] == L':')
-        {
-            auto uppercaseFirstLetter = std::move(path).native();
-            uppercaseFirstLetter[0] = nativePath[0] - L'a' + L'A';
-            path = uppercaseFirstLetter;
-        }
-#endif
-        (void)path;
-    }
-
 } // unnamed namespace
 
 namespace vcpkg
@@ -225,6 +214,10 @@ namespace vcpkg
         : m_pimpl(std::make_unique<details::VcpkgPathsImpl>(filesystem, args.compiler_tracking_enabled()))
     {
         original_cwd = filesystem.current_path(VCPKG_LINE_INFO);
+#if defined(_WIN32)
+        original_cwd = vcpkg::Files::win32_fix_path_case(original_cwd);
+#endif // _WIN32
+
         if (args.vcpkg_root_dir)
         {
             root = filesystem.canonical(VCPKG_LINE_INFO, fs::u8path(*args.vcpkg_root_dir));
@@ -238,7 +231,7 @@ namespace vcpkg
                     filesystem.canonical(VCPKG_LINE_INFO, System::get_exe_path_of_current_process()), ".vcpkg-root");
             }
         }
-        uppercase_win32_drive_letter(root);
+
         Checks::check_exit(VCPKG_LINE_INFO, !root.empty(), "Error: Could not detect vcpkg-root.");
         Debug::print("Using vcpkg-root: ", fs::u8string(root), '\n');
 
@@ -252,7 +245,6 @@ namespace vcpkg
         {
             manifest_root_dir = filesystem.find_file_recursively_up(original_cwd, fs::u8path("vcpkg.json"));
         }
-        uppercase_win32_drive_letter(manifest_root_dir);
 
         if (!manifest_root_dir.empty() && manifest_mode_on)
         {