add (likely, partial) windows implementation of POSIX realpath() for COMPILER_MINGW where the latter is not available, to the only place realpath() is used

libs/pbd/pathexpand.cc

@@ -33,12 +33,57 @@
 using std::string;
 using std::vector;
 
+#ifdef COMPILER_MINGW
+
+#include <WTypes.h>
+#include <glibmm.h>
+
+/****************************************************************
+ * Emulate POSIX realpath() using Win32 _fullpath() since realpath()
+ * is not available.
+ *
+ * Returns:
+ *    On Success: A pointer to the resolved (absolute) path
+ *    On Failure: 0 (NULL)
+ */
+
+static char* 
+realpath (const char *original_path, char resolved_path[_MAX_PATH+1])
+{
+	char *rpath = 0;
+	bool bIsSymLink = false; // We'll probably need to test the incoming path
+	                         // to find out if it points to a Windows shortcut
+	                         // (or a hard link) and set this appropriately.
+
+	if (bIsSymLink) {
+		// At the moment I'm not sure if Windows '_fullpath()' is directly
+		// equivalent to POSIX 'realpath()' - in as much as the latter will
+		// resolve the supplied path if it happens to point to a symbolic
+		// link ('_fullpath()' probably DOESN'T do this but I'm not really
+		// sure if Ardour needs such functionality anyway). Therefore we'll
+		// possibly need to add that functionality here at a later date.
+	} else {
+		char temp[(MAX_PATH+1)*6]; // Allow for maximum length of a path in wchar characters
+		
+		// POSIX 'realpath()' requires that the buffer size is at
+		// least PATH_MAX+1, so assume that the user knew this !!
+
+		rpath = _fullpath (temp, Glib::locale_from_utf8 (original_path).c_str(), _MAX_PATH);
+
+		if (0 != rpath) {
+			snprintf (resolved_path, _MAX_PATH+1, Glib::locale_to_utf8 (temp).c_str());
+		}
+			
+	}
+	
+	return (rpath);
+}
+
+#endif  // COMPILER_MINGW
+
 string
 PBD::canonical_path (const std::string& path)
 {
-#ifdef COMPILER_MINGW
-	return path;
-#else
 	char buf[PATH_MAX+1];
 
 	if (!realpath (path.c_str(), buf) && (errno != ENOENT)) {
@@ -46,7 +91,6 @@ PBD::canonical_path (const std::string& path)
 	}
 
 	return string (buf);
-#endif
 }
 
 string