don't crash if wrong input for command -recordfrom, strict arguments checking (#680)

src/d_main.c

@@ -1821,7 +1821,7 @@ int demowarp = -1;
 
 void D_DoomMain(void)
 {
-  int p, slot;
+  int p;
 
   setbuf(stdout,NULL);
 
@@ -2569,19 +2569,24 @@ void D_DoomMain(void)
   // Support -loadgame with -record and reimplement -recordfrom.
 
   //!
-  // @arg <save> <demo>
+  // @arg <savenum> <demofile>
   // @category demo
   //
-  // Records a demo starting from a saved game. It is the same as "-loadgame
-  // <save> -record <demo>". "-loadgame <save> -playdemo <demo>" plays back the
-  // demo starting from the saved game.
+  // Record a demo, loading from the given filename. Equivalent to -loadgame
+  // <savenum> -record <demofile>.
   //
 
-  if ((slot = M_CheckParm("-recordfrom")) && (p = slot+2) < myargc)
-    G_RecordDemo(myargv[p]);
+  p = M_CheckParmWithArgs("-recordfrom", 2);
+  if (p)
+  {
+    startloadgame = M_ParmArgToInt(p);
+    G_RecordDemo(myargv[p + 2]);
+  }
   else
     {
-      slot = M_CheckParm("-loadgame");
+      p = M_CheckParmWithArgs("-loadgame", 1);
+      if (p)
+        startloadgame = M_ParmArgToInt(p);
 
       //!
       // @arg <demo>
@@ -2627,11 +2632,6 @@ void D_DoomMain(void)
 	    demoskip_tics = -1;
 	  }
 
-  if (slot && ++slot < myargc)
-  {
-    startloadgame = atoi(myargv[slot]);
-  }
-
   // [FG] init graphics (WIDESCREENDELTA) before HUD widgets
   I_InitGraphics();
 

src/g_game.c

@@ -1699,6 +1699,7 @@ static void G_LoadGameErr(const char *msg)
   M_ForcedLoadGame(msg);             // Print message asking for 'Y' to force
   if (command_loadgame)              // If this was a command-line -loadgame
     {
+      G_CheckDemoStatus();           // If there was also a -record
       D_StartTitle();                // Start the title screen
       gamestate = GS_DEMOSCREEN;     // And set the game state accordingly
     }
@@ -3759,6 +3760,10 @@ boolean G_CheckDemoStatus(void)
   if (demorecording)
     {
       demorecording = false;
+
+      if (!demo_p)
+        return false;
+
       *demo_p++ = DEMOMARKER;
 
       G_AddDemoFooter();

src/m_argv.c

@@ -98,7 +98,25 @@ int M_ParmArg2ToInt(int p)
 #if defined(HAVE_PARAMS_GEN)
 #include "params.h"
 
-static int CheckArgs(int p, int num_args)
+static int CheckArgs(int p)
+{
+  int i;
+
+  ++p;
+
+  for (i = p; i < myargc; ++i)
+  {
+    if (myargv[i][0] == '-')
+      break;
+  }
+
+  if (i > p)
+    return i;
+
+  return 0;
+}
+
+static int CheckNumArgs(int p, int num_args)
 {
   int i;
 
@@ -110,7 +128,7 @@ static int CheckArgs(int p, int num_args)
       break;
   }
 
-  if (i > p)
+  if (i == p + num_args)
     return i;
 
   return 0;
@@ -123,7 +141,7 @@ void M_CheckCommandLine(void)
   while (p < myargc)
   {
     int i;
-    int args = -1;
+    int args = 0;
 
     for (i = 0; i < arrlen(params_with_args); ++i)
     {
@@ -131,7 +149,7 @@ void M_CheckCommandLine(void)
           !strcasecmp(myargv[p], "-deh")  ||
           !strcasecmp(myargv[p], "-bex"))
       {
-        args = myargc;
+        args = -1;
         break;
       }
       else if (!strcasecmp(myargv[p], "-warp") ||
@@ -147,14 +165,23 @@ void M_CheckCommandLine(void)
       }
     }
 
-    if (args > 0)
+    if (args)
     {
-      int check = CheckArgs(p, args);
+      int check = args > 0 ? CheckNumArgs(p, args) : CheckArgs(p);
 
       if (check)
       {
         p = check;
       }
+      // -warp can have only one parameter
+      else if (!strcasecmp(myargv[p], "-warp"))
+      {
+        check = CheckNumArgs(p, 1);
+        if (!check)
+          I_Error("No parameter for '-warp'.");
+        else
+          p = check;
+      }
       // -turbo has default value
       else if (!strcasecmp(myargv[p], "-turbo"))
       {