From 3fd2db56ad2d4621917215dd9e378d95bbc3021c Mon Sep 17 00:00:00 2001
From: Fabian Greffrath <fabian@greffrath.com>
Date: Sun, 14 May 2023 16:09:57 +0200
Subject: [PATCH] distinguish exit with message on error and on success (#1055)

---
 src/g_game.c   |  2 +-
 src/i_system.c | 12 +++++++++---
 src/i_system.h |  4 +++-
 src/w_wad.c    |  2 +-
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/g_game.c b/src/g_game.c
index a03478d4..0230d08f 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -3966,7 +3966,7 @@ boolean G_CheckDemoStatus(void)
       int endtime = I_GetTime_RealTime();
       // killough -- added fps information and made it work for longer demos:
       unsigned realtics = endtime-starttime;
-      I_Error ("Timed %u gametics in %u realtics = %-.1f frames per second",
+      I_Success("Timed %u gametics in %u realtics = %-.1f frames per second",
                (unsigned) gametic,realtics,
                (unsigned) gametic * (double) TICRATE / realtics);
     }
diff --git a/src/i_system.c b/src/i_system.c
index 925de518..fb0c93cb 100644
--- a/src/i_system.c
+++ b/src/i_system.c
@@ -75,8 +75,9 @@ static boolean I_ConsoleStdout(void)
 //
 
 static char errmsg[2048];    // buffer of error message -- killough
+static int exit_code;
 
-void I_Error(const char *error, ...) // killough 3/20/98: add const
+void I_ErrorOrSuccess(int err_code, const char *error, ...) // killough 3/20/98: add const
 {
     size_t len = sizeof(errmsg) - strlen(errmsg) - 1; // [FG] for '\n'
     char *dest = errmsg + strlen(errmsg);
@@ -89,7 +90,10 @@ void I_Error(const char *error, ...) // killough 3/20/98: add const
 
     fputs(dest, stderr);
 
-    I_SafeExit(-1);
+    if (exit_code == 0 && err_code != 0)
+        exit_code = err_code;
+
+    I_SafeExit(exit_code);
 }
 
 void I_ErrorMsg()
@@ -102,7 +106,9 @@ void I_ErrorMsg()
 
     if (*errmsg && !M_CheckParm("-nogui") && !I_ConsoleStdout())
     {
-        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR,
+        SDL_ShowSimpleMessageBox(exit_code == 0 ?
+                                 SDL_MESSAGEBOX_INFORMATION :
+                                 SDL_MESSAGEBOX_ERROR,
                                  PROJECT_STRING, errmsg, NULL);
     }
 }
diff --git a/src/i_system.h b/src/i_system.h
index b3d34056..0dbd1412 100644
--- a/src/i_system.h
+++ b/src/i_system.h
@@ -58,7 +58,9 @@ ticcmd_t* I_BaseTiccmd (void);
 
 // killough 3/20/98: add const
 // killough 4/25/98: add gcc attributes
-void I_Error(const char *error, ...) PRINTF_ATTR(1, 2);
+void I_ErrorOrSuccess(int err_code, const char *error, ...) PRINTF_ATTR(2, 3);
+#define I_Error(...) I_ErrorOrSuccess(-1, __VA_ARGS__)
+#define I_Success(...) I_ErrorOrSuccess(0, __VA_ARGS__)
 
 // Schedule a function to be called when the program exits.
 // If run_if_error is true, the function is called if the exit
diff --git a/src/w_wad.c b/src/w_wad.c
index 113f800b..250e43f8 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -523,7 +523,7 @@ void WriteLumpWad(const char *filename, const lumpinfo_t *lumps, const size_t nu
          fwrite(lumps[i].data, 1, lumps[i].size, file);
       
       fclose(file);
-      I_Error("Internal lumps wad, %s written, exiting\n", filename);
+      I_Success("Internal lumps wad, %s written, exiting\n", filename);
    }
    I_Error("Cannot open internal lumps wad %s for output\n", filename);
    free(fn);