Mercurial > sdl-ios-xcode
view src/SDL_getenv.c @ 638:b0108e9dea53
Date: Sun, 11 May 2003 19:59:06 +0300
From: Pasi K?rkk?inen
Subject: [PATCH] fix SDL OpenGL segfault with DRI/Mesa drivers and Glew
Hello!
The attached patch fixes a bug in SDL which causes SDL to crash in
X11_GL_Shutdown() if you are using DRI/Mesa drivers AND glew
(http://glew.sf.net).
The bug is caused by a namespace collision affecting dlsym() to fetch wrong
pointer for glXReleaseBuffersMESA() (uninitialized pointer from glew because
the extension is NOT supported by the driver) and then SDL calling it in
X11_GL_Shutdown().
SDL should check if the glXReleaseBuffersMESA() is really supported by the
driver (from the extensions string) before calling it.
Attached patch adds extension string parsing to check if
glXReleaseBuffersMESA() is really supported (and this way
prevents the segfault).
Availability of the extensions should be _always_ checked from the
extensions string rather than using dlsym()!
Please add it to the next version of SDL.
Thanks to gltron and author of glew to help fixing this.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 28 Jun 2003 17:27:33 +0000 |
parents | f6ffac90895c |
children | b8d311d90021 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #ifdef SAVE_RCSID static char rcsid = "@(#) $Id$"; #endif /* Not all environments have a working getenv()/putenv() */ #ifdef TEST_MAIN #define NEED_SDL_GETENV #endif #include "SDL_getenv.h" #ifdef NEED_SDL_GETENV #include <stdlib.h> #include <string.h> 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 = (char *)malloc(strlen(variable)+1); if ( ! new_variable ) { return(-1); } strcpy(new_variable, variable); /* 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 ( strncmp(SDL_env[i], name, len) == 0 ) { break; } } /* If we found it, just replace the entry */ if ( SDL_env[i] ) { 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 = 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 { 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 = strlen(name); for ( i=0; SDL_env[i] && !value; ++i ) { if ( (strncmp(SDL_env[i], name, len) == 0) && (SDL_env[i][len] == '=') ) { value = &SDL_env[i][len+1]; } } } return value; } #endif /* NEED_GETENV */ #ifdef TEST_MAIN #include <stdio.h> int main(int argc, char *argv[]) { char *value; printf("Checking for non-existent variable... "); fflush(stdout); if ( ! getenv("EXISTS") ) { printf("okay\n"); } else { printf("failed\n"); } printf("Setting FIRST=VALUE1 in the environment... "); fflush(stdout); if ( putenv("FIRST=VALUE1") == 0 ) { printf("okay\n"); } else { printf("failed\n"); } printf("Getting FIRST from the environment... "); fflush(stdout); value = getenv("FIRST"); if ( value && (strcmp(value, "VALUE1") == 0) ) { printf("okay\n"); } else { printf("failed\n"); } printf("Setting SECOND=VALUE2 in the environment... "); fflush(stdout); if ( putenv("SECOND=VALUE2") == 0 ) { printf("okay\n"); } else { printf("failed\n"); } printf("Getting SECOND from the environment... "); fflush(stdout); value = getenv("SECOND"); if ( value && (strcmp(value, "VALUE2") == 0) ) { printf("okay\n"); } else { printf("failed\n"); } printf("Setting FIRST=NOVALUE in the environment... "); fflush(stdout); if ( putenv("FIRST=NOVALUE") == 0 ) { printf("okay\n"); } else { printf("failed\n"); } printf("Getting FIRST from the environment... "); fflush(stdout); value = getenv("FIRST"); if ( value && (strcmp(value, "NOVALUE") == 0) ) { printf("okay\n"); } else { printf("failed\n"); } printf("Checking for non-existent variable... "); fflush(stdout); if ( ! getenv("EXISTS") ) { printf("okay\n"); } else { printf("failed\n"); } return(0); } #endif /* TEST_MAIN */