2 files changed, 95 insertions, 4 deletions

diff --git a/src/OSSupport/File.cpp b/src/OSSupport/File.cpp
index 7ad1b3f81..43105b230 100644
--- a/src/OSSupport/File.cpp
+++ b/src/OSSupport/File.cpp
@@ -456,17 +456,50 @@ AString cFile::ReadWholeFile(const AString & a_FileName)
 AString cFile::ChangeFileExt(const AString & a_FileName, const AString & a_NewExt)
 {
 	auto res = a_FileName;
+
+	// If the path separator is the last character of the string, return the string unmodified (refers to a folder):
+	#if defined(_MSC_VER)
+		// Find either path separator - MSVC CRT accepts slashes as separators, too
+		auto LastPathSep = res.find_last_of("/\\");
+	#elif defined(_WIN32)
+		// Windows with different CRTs support only the backslash separator
+		auto LastPathSep = res.rfind('\\');
+	#else
+		// Linux supports only the slash separator
+		auto LastPathSep = res.rfind('/');
+	#endif
+	if ((LastPathSep != AString::npos) && (LastPathSep + 1 == res.size()))
+	{
+		return res;
+	}
+
+	// Append or replace the extension:
 	auto DotPos = res.rfind('.');
-	if (DotPos == AString::npos)
+	if (
+		(DotPos == AString::npos) ||  // No dot found
+		((LastPathSep != AString::npos) && (LastPathSep > DotPos))  // Last dot is before the last path separator (-> in folder name)
+	)
 	{
-		// No extension, just append it:
-		res.push_back('.');
+		// No extension, just append the new one:
+		if (!a_NewExt.empty() && (a_NewExt[0] != '.'))
+		{
+			// a_NewExt doesn't start with a dot, insert one:
+			res.push_back('.');
+		}
 		res.append(a_NewExt);
 	}
 	else
 	{
 		// Replace existing extension:
-		res.erase(DotPos + 1, AString::npos);
+		if (!a_NewExt.empty() && (a_NewExt[0] != '.'))
+		{
+			// a_NewExt doesn't start with a dot, keep the current one:
+			res.erase(DotPos + 1, AString::npos);
+		}
+		else
+		{
+			res.erase(DotPos, AString::npos);
+		}
 		res.append(a_NewExt);
 	}
 	return res;
@@ -476,6 +509,52 @@ AString cFile::ChangeFileExt(const AString & a_FileName, const AString & a_NewEx
 
 
 
+unsigned cFile::GetLastModificationTime(const AString & a_FileName)
+{
+	struct stat st;
+	if (stat(a_FileName.c_str(), &st) < 0)
+	{
+		return 0;
+	}
+	#ifdef _WIN32
+		// Windows returns times in local time already
+		return static_cast<unsigned>(st.st_mtime);
+	#else
+		// Linux returns UTC time, convert to local timezone:
+		return static_cast<unsigned>(mktime(localtime(&st.st_mtime)));
+	#endif
+}
+
+
+
+
+
+AString cFile::GetPathSeparator(void)
+{
+	#ifdef _WIN32
+		return "\\";
+	#else
+		return "/";
+	#endif
+}
+
+
+
+
+
+AString cFile::GetExecutableExt(void)
+{
+	#ifdef _WIN32
+		return ".exe";
+	#else
+		return "";
+	#endif
+}
+
+
+
+
+
 int cFile::Printf(const char * a_Fmt, ...)
 {
 	AString buf;
diff --git a/src/OSSupport/File.h b/src/OSSupport/File.h
index 1cf5c71d7..6ee080480 100644
--- a/src/OSSupport/File.h
+++ b/src/OSSupport/File.h
@@ -131,6 +131,18 @@ public:
 	a_FileName may contain path specification. */
 	static AString ChangeFileExt(const AString & a_FileName, const AString & a_NewExt);
 
+	/** Returns the last modification time (in current timezone) of the specified file.
+	The value returned is in the same units as the value returned by time() function.
+	If the file is not found / accessible, zero is returned. */
+	static unsigned GetLastModificationTime(const AString & a_FileName);
+
+	/** Returns the path separator used by the current platform.
+	Note that the platform / CRT may support additional path separators (such as slashes on Windows), these don't get reported. */
+	static AString GetPathSeparator(void);
+
+	/** Returns the customary executable extension used by the current platform. */
+	static AString GetExecutableExt(void);
+
 	// tolua_end
 	
 	/** Returns the list of all items in the specified folder (files, folders, nix pipes, whatever's there). */