shithub: choc

Info  •  Files  •  Log  •  Branches

Don't successfully save a savegame if a buffer overrun occurs, and don't
overwrite the existing savegame.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 1119

--- a/NEWS

+++ b/NEWS

@@ -32,6 +32,9 @@

      * The default startup delay has been set to one second, to allow 

        time for the screen to settle before starting the game (some 

        monitors have a delay before they come back on after changing modes).

+     * If a savegame buffer overrun occurs, the savegame does not get saved

+       and existing savegames are not overwritten (same behaviour as 

+       Vanilla).

     Bugs fixed:

      * Desync with STRAIN demos and dehacked Misc values not being set

--- a/src/g_game.c

+++ b/src/g_game.c

@@ -1485,21 +1485,25 @@

 void G_DoSaveGame (void) 

 { 

-    char	name[100]; 

-    char*	description; 

-	

-    strcpy(name, P_SaveGameFile(savegameslot));

+    char *savegame_file;

+    char *temp_savegame_file;

-    description = savedescription; 

-	 

-    save_stream = fopen(name, "wb");

+    temp_savegame_file = P_TempSaveGameFile();

+    savegame_file = P_SaveGameFile(savegameslot);

+    // Open the savegame file for writing.  We write to a temporary file

+    // and then rename it at the end if it was successfully written.

+    // This prevents an existing savegame from being overwritten by 

+    // a corrupted one, or if a savegame buffer overrun occurs.

+

+    save_stream = fopen(temp_savegame_file, "wb");

+

     if (save_stream == NULL)

     {

         return;

     }

-    P_WriteSaveGameHeader(description);

+    P_WriteSaveGameHeader(savedescription);

     P_ArchivePlayers (); 

     P_ArchiveWorld (); 

@@ -1516,11 +1520,19 @@

         I_Error ("Savegame buffer overrun");

     }

+    // Finish up, close the savegame file.

+

     fclose(save_stream);

+    // Now rename the temporary savegame file to the actual savegame

+    // file, overwriting the old savegame if there was one there.

+

+    remove(savegame_file);

+    rename(temp_savegame_file, savegame_file);

+    

     gameaction = ga_nothing; 

     strcpy(savedescription, "");

-	 

+

     players[consoleplayer].message = DEH_String(GGSAVED);

     // draw the pattern into the back screen

--- a/src/p_saveg.c

+++ b/src/p_saveg.c

@@ -44,10 +44,35 @@

 FILE *save_stream;

 int savegamelength;

+// Get the filename of a temporary file to write the savegame to.  After

+// the file has been successfully saved, it will be renamed to the 

+// real file.

+

+char *P_TempSaveGameFile(void)

+{

+    static char *filename = NULL;

+

+    if (filename == NULL)

+    {

+        filename = malloc(strlen(savegamedir) + 32);

+    }

+

+    sprintf(filename, "%stemp.dsg", savegamedir);

+

+    return filename;

+}

+

+// Get the filename of the save game file to use for the specified slot.

+

 char *P_SaveGameFile(int slot)

 {

-    static char filename[256];

+    static char *filename = NULL;

     char basename[32];

+

+    if (filename == NULL)

+    {

+        filename = malloc(strlen(savegamedir) + 32);

+    }

     sprintf(basename, DEH_String(SAVEGAMENAME "%d.dsg"), slot);

--- a/src/p_saveg.h

+++ b/src/p_saveg.h

@@ -34,6 +34,10 @@

 #define SAVESTRINGSIZE 24

+// temporary filename to use while saving.

+

+char *P_TempSaveGameFile(void);

+

 // filename to use for a savegame slot

 char *P_SaveGameFile(int slot);