Stop fiddling around with jmp_buf.

Implement custom abort function handler for cleaning up CM after failed
server startup. Less hacky and more portable than previous solution that
involved swapping copies of jmp_buf around.

Fixes a weird Win64 crash when loading savegames.

6 files changed, 42 insertions, 30 deletions

diff --git a/inc/common/common.h b/inc/common/common.h
index 643a9f1..1ed0a20 100644
--- a/inc/common/common.h
+++ b/inc/common/common.h
@@ -21,7 +21,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "common/cmd.h"
 #include "common/utils.h"
-#include <setjmp.h>
 
 //
 // common.h -- definitions common between client and server, but not game.dll
@@ -83,6 +82,8 @@ typedef void (*rdflush_t)(int target, char *buffer, size_t len);
 void        Com_BeginRedirect(int target, char *buffer, size_t buffersize, rdflush_t flush);
 void        Com_EndRedirect(void);
 
+void        Com_AbortFunc(void (*func)(void *), void *arg);
+
 #ifdef _WIN32
 void        Com_AbortFrame(void);
 #endif
@@ -175,8 +176,6 @@ extern unsigned     time_before_ref;
 extern unsigned     time_after_ref;
 #endif
 
-extern jmp_buf      com_abortframe;
-
 extern const char   com_version_string[];
 
 extern unsigned     com_framenum;
diff --git a/src/common/common.c b/src/common/common.c
index 48a82ea..a136c43 100644
--- a/src/common/common.c
+++ b/src/common/common.c
@@ -49,7 +49,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "server/server.h"
 #include "system/system.h"
 
-jmp_buf  com_abortframe;    // an ERR_DROP occured, exit the entire frame
+#include <setjmp.h>
+
+static jmp_buf  com_abortframe;    // an ERR_DROP occured, exit the entire frame
+
+static void     (*com_abort_func)(void *);
+static void     *com_abort_arg;
 
 static qboolean com_errorEntered;
 static char     com_errorMsg[MAXERRORMSG]; // from Com_Printf/Com_Error
@@ -509,6 +514,12 @@ void Com_Error(error_type_t code, const char *fmt, ...)
     // abort any console redirects
     Com_AbortRedirect();
 
+    // call custom cleanup function if set
+    if (com_abort_func) {
+        com_abort_func(com_abort_arg);
+        com_abort_func = NULL;
+    }
+
     // reset Com_Printf recursion level
     com_printEntered = 0;
 
@@ -562,6 +573,12 @@ abort:
     longjmp(com_abortframe, -1);
 }
 
+void Com_AbortFunc(void (*func)(void *), void *arg)
+{
+    com_abort_func = func;
+    com_abort_arg = arg;
+}
+
 #ifdef _WIN32
 void Com_AbortFrame(void)
 {
diff --git a/src/server/commands.c b/src/server/commands.c
index 09a7990..b5c09fe 100644
--- a/src/server/commands.c
+++ b/src/server/commands.c
@@ -257,11 +257,16 @@ another level:
     map tram.cin+jail_e3
 ======================
 */
+
+static void abort_func(void *arg)
+{
+    CM_FreeMap(arg);
+}
+
 static void SV_Map(qboolean restart)
 {
     mapcmd_t    cmd;
     size_t      len;
-    jmp_buf     tmp;
 
     memset(&cmd, 0, sizeof(cmd));
 
@@ -275,15 +280,8 @@ static void SV_Map(qboolean restart)
     if (!SV_ParseMapCmd(&cmd))
         return;
 
-    // save error frame
-    memcpy(tmp, com_abortframe, sizeof(jmp_buf));
-
-    // catch ERR_DROP and free the map
-    if (setjmp(com_abortframe)) {
-        memcpy(com_abortframe, tmp, sizeof(jmp_buf));
-        CM_FreeMap(&cmd.cm);
-        return;
-    }
+    // save pending CM to be freed later if ERR_DROP is thrown
+    Com_AbortFunc(abort_func, &cmd.cm);
 
     // wipe savegames
     cmd.endofunit |= restart;
@@ -294,8 +292,8 @@ static void SV_Map(qboolean restart)
     if ((sv.state != ss_game && sv.state != ss_pic) || restart)
         SV_InitGame(MVD_SPAWN_DISABLED);    // the game is just starting
 
-    // restore error frame
-    memcpy(com_abortframe, tmp, sizeof(jmp_buf));
+    // clear pending CM
+    Com_AbortFunc(NULL, NULL);
 
     SV_SpawnServer(&cmd);
 
diff --git a/src/server/mvd/client.h b/src/server/mvd/client.h
index f2ec522..278fb3f 100644
--- a/src/server/mvd/client.h
+++ b/src/server/mvd/client.h
@@ -17,6 +17,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 #include "../server.h"
+#include <setjmp.h>
 
 #define MVD_Malloc(size)    Z_TagMalloc(size, TAG_MVD)
 #define MVD_Mallocz(size)   Z_TagMallocz(size, TAG_MVD)
@@ -187,6 +188,8 @@ extern qboolean         mvd_dirty;
 extern qboolean     mvd_active;
 extern unsigned     mvd_last_activity;
 
+extern jmp_buf  mvd_jmpbuf;
+
 #ifdef _DEBUG
 extern cvar_t    *mvd_shownet;
 #endif
diff --git a/src/server/mvd/game.c b/src/server/mvd/game.c
index 41eb7e1..db18ef4 100644
--- a/src/server/mvd/game.c
+++ b/src/server/mvd/game.c
@@ -38,8 +38,6 @@ mvd_client_t    *mvd_clients;
 
 mvd_player_t    mvd_dummy;
 
-extern jmp_buf  mvd_jmpbuf;
-
 static int      mvd_numplayers;
 
 static void MVD_UpdateClient(mvd_client_t *client);
diff --git a/src/server/save.c b/src/server/save.c
index a5d8eaf..4413cee 100644
--- a/src/server/save.c
+++ b/src/server/save.c
@@ -304,12 +304,16 @@ char *SV_GetSaveInfo(const char *dir)
     return Z_CopyString(va("%s %s", date, name));
 }
 
+static void abort_func(void *arg)
+{
+    CM_FreeMap(arg);
+}
+
 static int read_server_file(void)
 {
     char        name[MAX_OSPATH], string[MAX_STRING_CHARS];
     mapcmd_t    cmd;
     size_t      len;
-    jmp_buf     tmp;
 
     // errors like missing file, bad version, etc are
     // non-fatal and just return to the command handler
@@ -342,15 +346,8 @@ static int read_server_file(void)
     if (!SV_ParseMapCmd(&cmd))
         return -1;
 
-    // save error frame
-    memcpy(tmp, com_abortframe, sizeof(jmp_buf));
-
-    // catch ERR_DROP and free the map
-    if (setjmp(com_abortframe)) {
-        memcpy(com_abortframe, tmp, sizeof(jmp_buf));
-        CM_FreeMap(&cmd.cm);
-        return -1;
-    }
+    // save pending CM to be freed later if ERR_DROP is thrown
+    Com_AbortFunc(abort_func, &cmd.cm);
 
     // any error will drop from this point
     SV_Shutdown("Server restarted\n", ERR_RECONNECT);
@@ -389,8 +386,8 @@ static int read_server_file(void)
 
     ge->ReadGame(name);
 
-    // restore error frame
-    memcpy(com_abortframe, tmp, sizeof(jmp_buf));
+    // clear pending CM
+    Com_AbortFunc(NULL, NULL);
 
     // go to the map
     SV_SpawnServer(&cmd);