view src/stdlib/SDL_getenv.c @ 4168:69bcba65c388 SDL-1.2

Fixed bug #526 Comment #1 From Simon Howard 2009-03-20 16:50:56 Hi, I'm the author of Chocolate Doom, one of the other source ports that James mentioned. This is a patch against the current SVN version of SDL 1.2 that fixes the bug. It has been tested and hopefully should be obviously correct from examining the changes. I'll give a brief explanation. When the palette is set with SDL_SetPalette, the IDirectDrawPalette_SetEntries DirectX function is invoked. However, when this happens, a WM_PALETTECHANGED message is sent to the window. A WM_PALETTECHANGED message can also be received if the palette is changed for some other reason, like if the system palette is changed. Therefore, the palette change handler (DX5_PaletteChanged) has code to deal with this case. It distinguishes "expected" palette changes (set with SDL_SetPalette) from "unexpected" palette changes using the colorchange_expected variable, which is set before calling IDirectDrawPalette_SetEntries. However, the code to set this variable is missing in the fullscreen code path. By setting this variable, the palette change is handled properly and the freezes go away.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 13 Apr 2009 00:53:12 +0000
parents a1b03ba2fcd0
children
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#include "SDL_stdinc.h"

#ifndef HAVE_GETENV

#if defined(__WIN32__) && !defined(_WIN32_WCE) && !defined(__SYMBIAN32__)

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* Note this isn't thread-safe! */

static char *SDL_envmem = NULL;	/* Ugh, memory leak */
static size_t SDL_envmemlen = 0;

/* Put a variable of the form "name=value" into the environment */
int SDL_putenv(const char *variable)
{
	size_t bufferlen;
	char *value;
	const char *sep;

	sep = SDL_strchr(variable, '=');
	if ( sep == NULL ) {
		return -1;
	}
	bufferlen = SDL_strlen(variable)+1;
	if ( bufferlen > SDL_envmemlen ) {
		char *newmem = (char *)SDL_realloc(SDL_envmem, bufferlen);
		if ( newmem == NULL ) {
			return -1;
		}
		SDL_envmem = newmem;
		SDL_envmemlen = bufferlen;
	}
	SDL_strlcpy(SDL_envmem, variable, bufferlen);
	value = SDL_envmem + (sep - variable);
	*value++ = '\0';
	if ( !SetEnvironmentVariable(SDL_envmem, *value ? value : NULL) ) {
		return -1;
	}
	return 0;
}

/* Retrieve a variable named "name" from the environment */
char *SDL_getenv(const char *name)
{
	size_t bufferlen;

	bufferlen = GetEnvironmentVariable(name, SDL_envmem, (DWORD)SDL_envmemlen);
	if ( bufferlen == 0 ) {
		return NULL;
	}
	if ( bufferlen > SDL_envmemlen ) {
		char *newmem = (char *)SDL_realloc(SDL_envmem, bufferlen);
		if ( newmem == NULL ) {
			return NULL;
		}
		SDL_envmem = newmem;
		SDL_envmemlen = bufferlen;
		GetEnvironmentVariable(name, SDL_envmem, (DWORD)SDL_envmemlen);
	}
	return SDL_envmem;
}

#else /* roll our own */

static char **SDL_env = (char **)0;

/* Put a variable of the form "name=value" into the environment */
int SDL_putenv(const char *variable)
{
	const char *name, *value;
	int added;
	int len, i;
	char **new_env;
	char *new_variable;

	/* A little error checking */
	if ( ! variable ) {
		return(-1);
	}
	name = variable;
	for ( value=variable; *value && (*value != '='); ++value ) {
		/* Keep looking for '=' */ ;
	}
	if ( *value ) {
		++value;
	} else {
		return(-1);
	}

	/* Allocate memory for the variable */
	new_variable = SDL_strdup(variable);
	if ( ! new_variable ) {
		return(-1);
	}

	/* Actually put it into the environment */
	added = 0;
	i = 0;
	if ( SDL_env ) {
		/* Check to see if it's already there... */
		len = (value - name);
		for ( ; SDL_env[i]; ++i ) {
			if ( SDL_strncmp(SDL_env[i], name, len) == 0 ) {
				break;
			}
		}
		/* If we found it, just replace the entry */
		if ( SDL_env[i] ) {
			SDL_free(SDL_env[i]);
			SDL_env[i] = new_variable;
			added = 1;
		}
	}

	/* Didn't find it in the environment, expand and add */
	if ( ! added ) {
		new_env = SDL_realloc(SDL_env, (i+2)*sizeof(char *));
		if ( new_env ) {
			SDL_env = new_env;
			SDL_env[i++] = new_variable;
			SDL_env[i++] = (char *)0;
			added = 1;
		} else {
			SDL_free(new_variable);
		}
	}
	return (added ? 0 : -1);
}

/* Retrieve a variable named "name" from the environment */
char *SDL_getenv(const char *name)
{
	int len, i;
	char *value;

	value = (char *)0;
	if ( SDL_env ) {
		len = SDL_strlen(name);
		for ( i=0; SDL_env[i] && !value; ++i ) {
			if ( (SDL_strncmp(SDL_env[i], name, len) == 0) &&
			     (SDL_env[i][len] == '=') ) {
				value = &SDL_env[i][len+1];
			}
		}
	}
	return value;
}

#endif /* __WIN32__ */

#endif /* !HAVE_GETENV */

#ifdef TEST_MAIN
#include <stdio.h>

int main(int argc, char *argv[])
{
	char *value;

	printf("Checking for non-existent variable... ");
	fflush(stdout);
	if ( ! SDL_getenv("EXISTS") ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Setting FIRST=VALUE1 in the environment... ");
	fflush(stdout);
	if ( SDL_putenv("FIRST=VALUE1") == 0 ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Getting FIRST from the environment... ");
	fflush(stdout);
	value = SDL_getenv("FIRST");
	if ( value && (SDL_strcmp(value, "VALUE1") == 0) ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Setting SECOND=VALUE2 in the environment... ");
	fflush(stdout);
	if ( SDL_putenv("SECOND=VALUE2") == 0 ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Getting SECOND from the environment... ");
	fflush(stdout);
	value = SDL_getenv("SECOND");
	if ( value && (SDL_strcmp(value, "VALUE2") == 0) ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Setting FIRST=NOVALUE in the environment... ");
	fflush(stdout);
	if ( SDL_putenv("FIRST=NOVALUE") == 0 ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Getting FIRST from the environment... ");
	fflush(stdout);
	value = SDL_getenv("FIRST");
	if ( value && (SDL_strcmp(value, "NOVALUE") == 0) ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	printf("Checking for non-existent variable... ");
	fflush(stdout);
	if ( ! SDL_getenv("EXISTS") ) {
		printf("okay\n");
	} else {
		printf("failed\n");
	}
	return(0);
}
#endif /* TEST_MAIN */