Prepatory changes for moving to open

src/parser.cpp

@@ -1142,6 +1142,13 @@ bool is_safe_patch_path(const std::string& path)
     if (filesystem::is_absolute(path))
         return false;
 
+#ifdef _WIN32
+    // A colon never appears in a Windows file name. "C:foo" names foo relative to the current
+    // directory of drive C, and "file:stream" names an alternate data stream of "file".
+    if (path.find(':') != std::string::npos)
+        return false;
+#endif
+
     // Reject any '..' component, including one which would resolve back inside the working directory
     for (std::size_t begin = 0; begin < path.size();) {
         std::size_t end = begin;

src/patch.cpp

@@ -456,9 +456,8 @@ class DeferredWriter {
     std::vector<StagedReplacement> m_deferred_writes;
 };
 
-static bool refuse_read_only_file(std::ostream& out, const Options& options, const std::string& output_file)
+static bool refuse_read_only_file(std::ostream& out, const Options& options, const std::string& output_file, filesystem::perms permissions)
 {
-    const auto permissions = filesystem::get_permissions(output_file);
     const auto write_perm_mask = filesystem::perms::group_write | filesystem::perms::owner_write | filesystem::perms::others_write;
     const bool is_read_only = permissions != filesystem::perms::unknown
         && (permissions & write_perm_mask) == filesystem::perms::none;
@@ -569,7 +568,7 @@ static bool process_parsed_patch(const Options& options, DeferredWriter& deferre
         return true;
     }
 
-    if (refuse_read_only_file(out, options, output_file)) {
+    if (refuse_read_only_file(out, options, output_file, filesystem::get_permissions(output_file))) {
         parse_body_if_needed();
         refuse_to_patch(out, mode, output_file, patch, options);
         return true;

src/system.cpp

@@ -298,8 +298,8 @@ bool is_absolute(const std::string& path)
         return true;
 
 #ifdef _WIN32
-    // A drive letter, with or without a following separator.
-    return path.size() >= 2 && path[1] == ':';
+    // A drive letter, with a following separator.
+    return path.size() >= 3 && path[1] == ':' && is_seperator(path[2]);
 #else
     return false;
 #endif

tests/lib/include/patch/test.h

@@ -15,6 +15,10 @@
 
 namespace Patch {
 
+bool file_exists(const std::string& path);
+
+bool create_directory(const std::string& path);
+
 void unset_env(const char* name);
 
 void set_env(const char* name, const char* value);

tests/lib/src/test.cpp

@@ -17,6 +17,16 @@
 
 namespace Patch {
 
+bool file_exists(const std::string& path)
+{
+    return filesystem::exists(path);
+}
+
+bool create_directory(const std::string& path)
+{
+    return filesystem::create_directory(path);
+}
+
 enum class Outcome {
     Passed,
     Failed,
@@ -32,8 +42,9 @@ static std::string make_temp_directory()
 {
 #ifdef _WIN32
     std::wstring path = L"patch-XXXXXX";
-    if (_wmktemp_s(&path[0], path.size() + 1) < 0)
-        throw std::system_error(errno, std::generic_category(), "Unable to create temporary file name");
+    const auto error = _wmktemp_s(&path[0], path.size() + 1);
+    if (error != 0)
+        throw std::system_error(error, std::generic_category(), "Unable to create temporary file name");
     if (_wmkdir(path.c_str()) < 0)
         throw std::system_error(errno, std::generic_category(), "Unable to make temporary directory");
     return to_narrow(path);