Server: Backport 0017-Fix-city-removal-server-crashes.patch

Signed-off-by: Marko Lindqvist <[email protected]>

freeciv/apply_patches.sh

@@ -21,6 +21,9 @@
 # 0014-Improve-savemain.c-coding-style.patch
 #   Baseline for freeciv-web patches
 #   RM #79
+# 0017-Fix-city-removal-server-crashes.patch
+#   Crash fix
+#   RM #81
 
 # Not in the upstream Freeciv server
 # ----------------------------------
@@ -48,6 +51,7 @@ declare -a PATCHLIST=(
   "backports/0029-universal_value_initial-Fix-switch-case-fall-through"
   "backports/0031-Meson-Enable-implicit-fallthrough-compiler-warnings"
   "backports/0014-Improve-savemain.c-coding-style"
+  "backports/0017-Fix-city-removal-server-crashes"
   "meson_webperimental"
   "metachange"
   "text_fixes"

freeciv/patches/backports/0017-Fix-city-removal-server-crashes.patch

@@ -0,0 +1,55 @@
+From 37508b45f7591f3acb749afb223aeefcaeb76749 Mon Sep 17 00:00:00 2001
+From: Marko Lindqvist <[email protected]>
+Date: Wed, 27 Dec 2023 15:11:56 +0200
+Subject: [PATCH 17/17] Fix city removal server crashes
+
+When city removal wipes a unit that's not homed to the city,
+but on the same tile, recursive city refresh was crashing
+due to city vision and advisor data being already deleted.
+
+See RM #81
+
+Signed-off-by: Marko Lindqvist <[email protected]>
+---
+ server/citytools.c | 17 +++++++++++------
+ 1 file changed, 11 insertions(+), 6 deletions(-)
+
+diff --git a/server/citytools.c b/server/citytools.c
+index f760deb3e0..87917e0b77 100644
+--- a/server/citytools.c
++++ b/server/citytools.c
+@@ -3416,11 +3416,13 @@ void city_landlocked_sell_coastal_improvements(struct tile *ptile)
+ ****************************************************************************/
+ void city_refresh_vision(struct city *pcity)
+ {
+-  v_radius_t vision_radius_sq
+-    = V_RADIUS(get_city_bonus(pcity, EFT_CITY_VISION_RADIUS_SQ), 2, 2);
++  if (pcity->server.vision != nullptr) {
++    v_radius_t vision_radius_sq
++      = V_RADIUS(get_city_bonus(pcity, EFT_CITY_VISION_RADIUS_SQ), 2, 2);
+
+-  vision_change_sight(pcity->server.vision, vision_radius_sq);
+-  ASSERT_VISION(pcity->server.vision);
++    vision_change_sight(pcity->server.vision, vision_radius_sq);
++    ASSERT_VISION(pcity->server.vision);
++  }
+ }
+
+ /************************************************************************//**
+@@ -3525,8 +3527,11 @@ bool city_map_update_radius_sq(struct city *pcity)
+     city_refresh_vision(pcity);
+   }
+
+-  /* If city is under AI control, update it */
+-  adv_city_update(pcity);
++  /* City removal might be ongoing, and advisor data already deleted */
++  if (pcity->server.adv != nullptr) {
++    /* If city is under AI control, update it */
++    adv_city_update(pcity);
++  }
+
+   notify_player(city_owner(pcity), city_tile(pcity), E_CITY_RADIUS_SQ,
+                 ftc_server, _("The size of the city map of %s is %s."),
+-- 
+2.43.0
+