Fallback to getpwuid() if $HOME is unset

This commit makes the game fallback to using getpwuid() for retrieving
information about the user's home directory, should $HOME be unset.

prboom2/CMakeLists.txt

@@ -94,8 +94,10 @@ check_symbol_exists(mkstemp "stdlib.h" HAVE_MKSTEMP)
 
 include(CheckIncludeFile)
 
+check_include_file("sys/types.h" HAVE_SYS_TYPES_H)
 check_include_file("sys/wait.h" HAVE_SYS_WAIT_H)
 check_include_file("unistd.h" HAVE_UNISTD_H)
+check_include_file("pwd.h" HAVE_PWD_H)
 check_include_file("asm/byteorder.h" HAVE_ASM_BYTEORDER_H)
 check_include_file("dirent.h" HAVE_DIRENT_H)
 

prboom2/cmake/config.h.cin

@@ -15,8 +15,10 @@
 #cmakedefine HAVE_STRSIGNAL
 #cmakedefine HAVE_MKSTEMP
 
+#cmakedefine HAVE_SYS_TYPES_H
 #cmakedefine HAVE_SYS_WAIT_H
 #cmakedefine HAVE_UNISTD_H
+#cmakedefine HAVE_PWD_H
 #cmakedefine HAVE_ASM_BYTEORDER_H
 #cmakedefine HAVE_DIRENT_H
 

prboom2/src/SDL/i_system.c

@@ -56,6 +56,13 @@
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#ifdef HAVE_PWD_H
+#ifdef HAVE_SYS_TYPES_H
+#include <pwd.h>
+#include <sys/types.h>
+#define GETPWUID_FALLBACK
+#endif
+#endif
 #endif
 
 #ifdef _MSC_VER
@@ -316,6 +323,13 @@ const char *I_ConfigDir(void)
     if (!home)
     {
       home = "/";
+
+#ifdef GETPWUID_FALLBACK
+      struct passwd *user_info = getpwuid(getuid());
+      if (user_info != NULL) {
+        home = user_info->pw_dir;
+      }
+#endif
     }
 
     // First, try legacy directory.