Merge pull request scp-fs2open#5976 from notimaginative/fix_cmdline_m…

…od_on_unix

refactor unix modlist handling to fix serveral issues

code/cmdline/cmdline.cpp

@@ -40,6 +40,7 @@
 #ifdef SCP_UNIX
 #include "osapi/osapi.h"
 #include <dirent.h>
+#include <sys/stat.h>
 #endif
 
 #include <cstring>
@@ -1208,93 +1209,133 @@ bool cmdline_parm::has_param() {
 }
 
 #ifdef SCP_UNIX
-// Return a vector with all filesystem names of "parent/dir" relative to parent.
-// dir must not contain a slash.
-static SCP_vector<SCP_string> unix_get_single_dir_names(const SCP_string& parent, const SCP_string& dir)
+extern void normalize_directory_separators(SCP_string &str);
+
+static SCP_string get_real_mod_path(const char *mod)
 {
-	SCP_vector<SCP_string> ret;
+	DIR *dirp;
+	SCP_string fullpath;
+	SCP_string mod_path = mod;
+
+	normalize_directory_separators(mod_path);
+
+	fullpath = SCP_string(".") + DIR_SEPARATOR_STR;
+	fullpath += mod_path;
+
+	// check if path already exists
+	dirp = opendir(fullpath.c_str());
+
+	if (dirp) {
+		// found it, return unchanged
+		closedir(dirp);
 
-	DIR *dp;
-	if ((dp = opendir(parent.c_str())) == NULL) {
-		Warning(LOCATION, "Can't open directory '%s' when searching mod paths. Ignoring. errno=%d", parent.c_str(), errno);
-		return ret;
+		return mod_path;
 	}
 
-	dirent *dirp;
-	while ((dirp = readdir(dp)) != NULL) {
-		if (!stricmp(dirp->d_name, dir.c_str())) {
-			ret.push_back(dirp->d_name);
+	// not found, check for a difference in case
+	SCP_string new_mod_path;
+	SCP_string part;
+	struct dirent *dir;
+	SCP_string::size_type separator;
+	SCP_string::size_type offset = 0;
+
+	fullpath = SCP_string(".") + DIR_SEPARATOR_STR;
+
+	do {
+		separator = mod_path.find(DIR_SEPARATOR_CHAR, offset);
+
+		if (separator != SCP_string::npos) {
+			part = mod_path.substr(offset, separator-offset);
+			offset += separator-offset + 1;
+		} else {
+			part = mod_path.substr(offset);
+			offset += part.length();
 		}
-	}
-	(void)closedir(dp);
 
-	return ret;
-}
+		dirp = opendir(fullpath.c_str());
 
-// Return a vector with all filesystem names of "parent/dir" relative to parent.
-// Recurses to deal with slashes in dir.
-static SCP_vector<SCP_string> unix_get_dir_names(const SCP_string& parent, const SCP_string& dir)
-{
-	size_t slash = dir.find_first_of("/\\");
+		if ( !dirp ) {
+			break;
+		}
 
-	// no subdirectories, no need to recurse
-	if (slash == std::string::npos) {
-		return unix_get_single_dir_names(parent, dir);
-	}
+		while ((dir = readdir(dirp)) != nullptr) {
+			if (stricmp(dir->d_name, part.c_str())) {
+				continue;
+			}
 
-	// get the names of the first component of dir
-	SCP_vector<SCP_string> this_dir_names = unix_get_single_dir_names(parent, dir.substr(0, slash));
+			SCP_string fn = fullpath + dir->d_name;
 
-	SCP_string rest = dir.substr(slash + 1);
+			// make sure it accessible and a directory
+			struct stat buf;
 
-	SCP_vector<SCP_string> ret;
+			if (stat(fn.c_str(), &buf) == -1) {
+				continue;
+			}
 
-	// search for the rest of dir in each of these
-	SCP_vector<SCP_string>::iterator ii, end = this_dir_names.end();
-	for (ii = this_dir_names.begin(); ii != end; ++ii) {
-		SCP_string this_dir_path = parent + "/" + *ii;
-		SCP_vector<SCP_string> mod_path = unix_get_dir_names(this_dir_path, rest);
+			if ( !S_ISDIR(buf.st_mode) ) {
+				continue;
+			}
+
+			if ( !new_mod_path.empty() ) {
+				new_mod_path += DIR_SEPARATOR_STR;
+			}
+
+			new_mod_path += dir->d_name;
+
+			fullpath += dir->d_name;
+			fullpath += DIR_SEPARATOR_STR;
+
+			break;
+		}
 
-		// add all found paths relative to parent
-		SCP_vector<SCP_string>::iterator ii2, end2 = mod_path.end();
-		for (ii2 = mod_path.begin(); ii2 != end2; ++ii2) {
-			ret.push_back(*ii + "/" + *ii2);
+		if (dirp) {
+			closedir(dirp);
 		}
+	} while (offset < mod_path.length());
+
+	// Append anything left from mod_path onto the new path. This will catch trailing separators
+	// as well as mod folders which don't exist so that the mod string remains unchanged except
+	// for the directory name case.
+	if (new_mod_path.length() != mod_path.length()) {
+		new_mod_path += mod_path.substr(new_mod_path.length());
 	}
 
-	return ret;
+	return new_mod_path;
 }
 
 // For case sensitive filesystems (e.g. Linux/BSD) perform case-insensitive dir matches.
+//
+// NOTE: Aside from change in case no alterations should be made to the modlist. Missing
+//       mod folders should be left in place and no errors or warnings should be generated.
+//       There should be no difference between Windows and non-Windows modlist handling.
 static void handle_unix_modlist(char **modlist, size_t *len)
 {
 	// search filesystem for given paths
 	SCP_vector<SCP_string> mod_paths;
-	for (char *cur_mod = strtok(*modlist, ","); cur_mod != NULL; cur_mod = strtok(NULL, ","))
-	{
-		SCP_vector<SCP_string> this_mod_paths = unix_get_dir_names(".", cur_mod);
-		// Ignore non-existing mods for unit tests
-		if (!running_unittests && this_mod_paths.empty()) {
-			ReleaseWarning(LOCATION, "Can't find mod '%s'. Ignoring.", cur_mod);
-		}
-		mod_paths.insert(mod_paths.end(), this_mod_paths.begin(), this_mod_paths.end());
+
+	for (char *cur_mod = strtok(*modlist, ","); cur_mod != NULL; cur_mod = strtok(NULL, ",")) {
+		SCP_string path = get_real_mod_path(cur_mod);
+		mod_paths.push_back(path);
 	}
 
 	// create new char[] to replace modlist
 	size_t total_len = 0;
-	SCP_vector<SCP_string>::iterator ii, end = mod_paths.end();
-	for (ii = mod_paths.begin(); ii != end; ++ii) {
-		total_len += ii->length() + 1;
+
+	for (auto &path : mod_paths) {
+		total_len += path.length() + 1;
 	}
 
 	char *new_modlist = new char[total_len + 1];
 	memset(new_modlist, 0, total_len + 1);
-	end = mod_paths.end();
-	for (ii = mod_paths.begin(); ii != end; ++ii) {
-		strcat_s(new_modlist, total_len + 1, ii->c_str());
-		strcat_s(new_modlist, total_len + 1, ","); // replace later with NUL
+
+	for (auto &path : mod_paths) {
+		strcat_s(new_modlist, total_len + 1, path.c_str());
+		strcat_s(new_modlist, total_len + 1, ",");
 	}
 
+	// remove trailing comma
+	new_modlist[total_len-1] = '\0';
+
 	// make the rest of the modlist manipulation unaware that anything happened here
 	delete [] *modlist;
 	*modlist = new_modlist;
@@ -1799,7 +1840,7 @@ bool SetCmdlineParams()
 	if(mod_arg.found() ) {
 		Cmdline_mod = mod_arg.str();
 
-		// strip off blank space it it's there
+		// strip off blank space if it's there
 		if ( Cmdline_mod[strlen(Cmdline_mod)-1] == ' ' ) {
 			Cmdline_mod[strlen(Cmdline_mod)-1] = '\0';
 		}