Add a `SECTIONRACE` map flag. So far, all it does is prevent the number of laps from exceeding the map default, but it's a base to work off of if we want to add any other changes specifically for section races in future.

src/dehacked.c

@@ -1308,6 +1308,13 @@ static void readlevelheader(MYFILE *f, INT32 num)
 				else
 					mapheaderinfo[num-1]->levelflags &= ~LF_NOZONE;
 			}
+			else if (fastcmp(word, "SECTIONRACE"))
+			{
+				if (i || word2[0] == 'T' || word2[0] == 'Y')
+					mapheaderinfo[num-1]->levelflags |= LF_SECTIONRACE;
+				else
+					mapheaderinfo[num-1]->levelflags &= ~LF_SECTIONRACE;
+			}
 
 			// Individual triggers for menu flags
 			else if (fastcmp(word, "HIDDEN"))
@@ -7943,6 +7950,7 @@ struct {
 	{"LF_NOSSMUSIC",LF_NOSSMUSIC},
 	{"LF_NORELOAD",LF_NORELOAD},
 	{"LF_NOZONE",LF_NOZONE},
+	{"LF_SECTIONRACE",LF_SECTIONRACE},
 	// And map flags
 	{"LF2_HIDEINMENU",LF2_HIDEINMENU},
 	{"LF2_HIDEINSTATS",LF2_HIDEINSTATS},

src/doomstat.h

@@ -272,6 +272,7 @@ typedef struct
 #define LF_NOSSMUSIC      4 ///< Disable Super Sonic music
 #define LF_NORELOAD       8 ///< Don't reload level on death
 #define LF_NOZONE        16 ///< Don't include "ZONE" on level title
+#define LF_SECTIONRACE   32 ///< Section race level
 
 #define LF2_HIDEINMENU     1 ///< Hide in the multiplayer menu
 #define LF2_HIDEINSTATS    2 ///< Hide in the statistics screen

src/p_setup.c

@@ -2916,7 +2916,9 @@ boolean P_SetupLevel(boolean skipprecip)
 	}
 	else if (G_RaceGametype() && server)
 		CV_StealthSetValue(&cv_numlaps,
-			((netgame || multiplayer) && cv_basenumlaps.value)
+			((netgame || multiplayer) && cv_basenumlaps.value
+				&& (!(mapheaderinfo[gamemap - 1]->levelflags & LF_SECTIONRACE)
+					|| (mapheaderinfo[gamemap - 1]->numlaps > cv_basenumlaps.value)))
 			? cv_basenumlaps.value
 			: mapheaderinfo[gamemap - 1]->numlaps);