From c77756e6fe793ff80d36a39b711b00e8aa53a47d Mon Sep 17 00:00:00 2001
From: Steven Fuller <relnev@icculus.org>
Date: Wed, 15 Oct 2003 02:56:47 +0000
Subject: [PATCH] changed FixFilename to only lowercase the game-supplied part
 of a filename.

added better game directory detection code.  now each candidate directory
is checked for validity.
---
 src/files.c |  11 ++--
 src/main.c  | 141 ++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 138 insertions(+), 14 deletions(-)

diff --git a/src/files.c b/src/files.c
index 042441b..b25ddbe 100644
--- a/src/files.c
+++ b/src/files.c
@@ -44,15 +44,19 @@ static char *FixFilename(const char *filename, const char *prefix, int force)
 {
 	char *f, *ptr;
 	int flen;
+	int plen;
 	
-	flen = strlen(filename) + strlen(prefix) + 2;
+	plen = strlen(prefix) + 1;
+	flen = strlen(filename) + plen + 1;
 	
 	f = (char *)malloc(flen);
 	strcpy(f, prefix);
 	strcat(f, DIR_SEPARATOR);
 	strcat(f, filename);
 	
-	ptr = f;
+	/* only the filename part needs to be modified */
+	ptr = &f[plen+1];
+	
 	while (*ptr) {
 		if ((*ptr == '/') || (*ptr == '\\') || (*ptr == ':')) {
 			*ptr = DIR_SEPARATOR[0];
@@ -60,8 +64,9 @@ static char *FixFilename(const char *filename, const char *prefix, int force)
 			*ptr = 0;
 			break;
 		} else {
-			if (force)
+			if (force) {
 				*ptr = tolower(*ptr);
+			}
 		}
 		ptr++;
 	}
diff --git a/src/main.c b/src/main.c
index 22918df..3a3ae71 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <unistd.h>
+#include <assert.h>
 
 #include "SDL.h"
 #include <GL/gl.h>
@@ -1080,19 +1082,63 @@ void FlipBuffers()
 
 char *AvpCDPath = 0;
 
+static int try_game_directory(char *dir, char *file)
+{
+	char tmppath[PATH_MAX];
+
+	strncpy(tmppath, dir, PATH_MAX-32);
+	tmppath[PATH_MAX-32] = 0;
+	strcat(tmppath, file);
+	
+	return access(tmppath, R_OK) == 0;
+}
+
+static int check_game_directory(char *dir)
+{
+	if (!dir || !*dir) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/avp_huds")) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/avp_huds/alien.rif")) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/avp_rifs")) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/avp_rifs/temple.rif")) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/fastfile")) {
+		return 0;
+	}
+	
+	if (!try_game_directory(dir, "/fastfile/ffinfo.txt")) {
+		return 0;
+	}
+	
+	return 1;
+}
+
 void InitGameDirectories(char *argv0)
 {
 	extern char *SecondTex_Directory;
 	extern char *SecondSoundDir;
+	
+	char tmppath[PATH_MAX];
 	char *homedir, *gamedir, *localdir, *tmp;
+	char *path;
+	size_t len, copylen;
 	
 	SecondTex_Directory = "graphics/";
 	SecondSoundDir = "sound/";
-/* 
- 	printf("argv[0] = %s\n", argv0);
-	printf("$HOME = %s\n", getenv("HOME"));
-	printf("$AVP_DATA = %s\n", getenv("AVP_DATA"));
-*/
+
 	homedir = getenv("HOME");
 	if (homedir == NULL)
 		homedir = ".";
@@ -1103,26 +1149,99 @@ void InitGameDirectories(char *argv0)
 	
 	tmp = NULL;
 	
-	/* TODO: for each step, check existance of avp_rifs directory? */
+	/*
+	1. $AVP_DATA overrides all
+	2. executable path from argv[0]
+	3. realpath of executable path from argv[0]
+	4. $PATH
+	5. current directory
+	*/
+	
+	/* 1. $AVP_DATA */
 	gamedir = getenv("AVP_DATA");
+	
+	/* $AVP_DATA overrides all, so no check */
+	
 	if (gamedir == NULL) {
+		/* 2. executable path from argv[0] */
 		tmp = strdup(argv0);
 		
+		if (tmp == NULL) {
+			/* ... */
+			fprintf(stderr, "InitGameDirectories failure\n");
+			exit(EXIT_FAILURE);
+		}
+
 		gamedir = strrchr(tmp, '/');
-		if (gamedir == NULL) {
-			gamedir = ".";
-		} else {
+
+		if (gamedir) {
 			*gamedir = 0;
 			gamedir = tmp;
+		
+			if (!check_game_directory(gamedir)) {
+				gamedir = NULL;
+			}
 		}
 	}
 	
+	if (gamedir == NULL) {
+		/* 3. realpath of executable path from argv[0] */
+		
+		assert(tmp != NULL);
+
+		gamedir = realpath(tmp, tmppath);
+
+		if (!check_game_directory(gamedir)) {
+			gamedir = NULL;
+		}
+	}
+
+	if (gamedir == NULL) {
+		/* 4. $PATH */
+		path = getenv("PATH");
+		if (path) {
+			while (*path) {
+				len = strcspn(path, ":");
+				
+				copylen = min(len, PATH_MAX-1);
+				
+				strncpy(tmppath, path, copylen);
+				tmppath[copylen] = 0;
+				
+				if (check_game_directory(tmppath)) {
+					gamedir = tmppath;
+					break;
+				}
+				
+				path += len;
+				path += strspn(path, ":");
+			}
+		}
+	}
+	
+	if (gamedir == NULL) {
+		/* 5. current directory */
+		gamedir = ".";
+	}
+	
+	assert(gamedir != NULL);
+	
+	/* last chance sanity check */
+	if (!check_game_directory(gamedir)) {
+		fprintf(stderr, "Unable to find the AvP gamedata.\n");
+		fprintf(stderr, "The directory last examined was: %s\n", gamedir);
+		fprintf(stderr, "Has the game been installed and\n");
+		fprintf(stderr, "are all game files lowercase?\n");
+		exit(EXIT_FAILURE);
+	}
+
 	SetGameDirectories(localdir, gamedir);
 	
 	free(localdir);
-	if (tmp)
+	if (tmp) {
 		free(tmp);
-		
+	}
+	
 	/* delete some log files */
 	DeleteGameFile("dx_error.log");
 }