From 061a5e08dfc27449ea7265a36155e33883f00afe Mon Sep 17 00:00:00 2001
From: Nick Drabsch <zero@hypixelstudios.com>
Date: Sun, 9 Jul 2023 12:57:40 +0100
Subject: [PATCH] Prevent index 0 in ecs_field functions

---
 flecs.c    | 85 +++++++++++++++++++-----------------------------------
 src/iter.c | 85 +++++++++++++++++++-----------------------------------
 2 files changed, 58 insertions(+), 112 deletions(-)

diff --git a/flecs.c b/flecs.c
index ec102d541..b8fb231b5 100644
--- a/flecs.c
+++ b/flecs.c
@@ -59465,68 +59465,53 @@ bool flecs_iter_next_instanced(
 void* ecs_field_w_size(
     const ecs_iter_t *it,
     size_t size,
-    int32_t term)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(it->ptrs != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(!size || ecs_field_size(it, term) == size || 
-        (!ecs_field_size(it, term) && (!it->ptrs[term - 1])), 
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+
+    ecs_check(!size || ecs_field_size(it, index) == size ||
+        (!ecs_field_size(it, index) && (!it->ptrs[index - 1])),
             ECS_INVALID_PARAMETER, NULL);
     (void)size;
 
-    if (!term) {
-        return it->entities;
-    }
-
-    return it->ptrs[term - 1];
+    return it->ptrs[index - 1];
 error:
     return NULL;
 }
 
 bool ecs_field_is_readonly(
     const ecs_iter_t *it,
-    int32_t term_index)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(term_index > 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    ecs_term_t *term = &it->terms[index - 1];
 
-    ecs_term_t *term = &it->terms[term_index - 1];
-    ecs_check(term != NULL, ECS_INVALID_PARAMETER, NULL);
-    
     if (term->inout == EcsIn) {
         return true;
-    } else {
-        ecs_term_id_t *src = &term->src;
-
-        if (term->inout == EcsInOutDefault) {
-            if (!(ecs_term_match_this(term))) {
-                return true;
-            }
+    } else if (term->inout == EcsInOutDefault) {
+        if (!ecs_term_match_this(term)) {
+            return true;
+        }
 
-            if (!(src->flags & EcsSelf)) {
-                return true;
-            }
+        ecs_term_id_t *src = &term->src;
+        if (!(src->flags & EcsSelf)) {
+            return true;
         }
     }
-
 error:
     return false;
 }
 
 bool ecs_field_is_writeonly(
     const ecs_iter_t *it,
-    int32_t term_index)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(term_index > 0, ECS_INVALID_PARAMETER, NULL);
-
-    ecs_term_t *term = &it->terms[term_index - 1];
-    ecs_check(term != NULL, ECS_INVALID_PARAMETER, NULL);
-    
-    if (term->inout == EcsOut) {
-        return true;
-    }
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    ecs_term_t *term = &it->terms[index - 1];
+    return term->inout == EcsOut;
 error:
     return false;
 }
@@ -59536,7 +59521,7 @@ bool ecs_field_is_set(
     int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     int32_t column = it->columns[index - 1];
     if (!column) {
         return false;
@@ -59549,7 +59534,6 @@ bool ecs_field_is_set(
             return true;
         }
     }
-
     return true;
 error:
     return false;
@@ -59559,8 +59543,7 @@ bool ecs_field_is_self(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     return it->sources == NULL || it->sources[index - 1] == 0;
 }
 
@@ -59568,8 +59551,7 @@ ecs_id_t ecs_field_id(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     return it->ids[index - 1];
 }
 
@@ -59577,23 +59559,20 @@ int32_t ecs_field_column_index(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     int32_t result = it->columns[index - 1];
     if (result <= 0) {
         return -1;
+    } else {
+        return result - 1;
     }
-
-    return result - 1;
 }
 
 ecs_entity_t ecs_field_src(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     if (it->sources) {
         return it->sources[index - 1];
     } else {
@@ -59605,14 +59584,8 @@ size_t ecs_field_size(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
-
-    if (index == 0) {
-        return sizeof(ecs_entity_t);
-    } else {
-        return (size_t)it->sizes[index - 1];
-    }
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    return (size_t)it->sizes[index - 1];
 }
 
 char* ecs_iter_str(
diff --git a/src/iter.c b/src/iter.c
index 6b27401e2..1f4dde011 100644
--- a/src/iter.c
+++ b/src/iter.c
@@ -348,68 +348,53 @@ bool flecs_iter_next_instanced(
 void* ecs_field_w_size(
     const ecs_iter_t *it,
     size_t size,
-    int32_t term)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(it->ptrs != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(!size || ecs_field_size(it, term) == size || 
-        (!ecs_field_size(it, term) && (!it->ptrs[term - 1])), 
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+
+    ecs_check(!size || ecs_field_size(it, index) == size ||
+        (!ecs_field_size(it, index) && (!it->ptrs[index - 1])),
             ECS_INVALID_PARAMETER, NULL);
     (void)size;
 
-    if (!term) {
-        return it->entities;
-    }
-
-    return it->ptrs[term - 1];
+    return it->ptrs[index - 1];
 error:
     return NULL;
 }
 
 bool ecs_field_is_readonly(
     const ecs_iter_t *it,
-    int32_t term_index)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(term_index > 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    ecs_term_t *term = &it->terms[index - 1];
 
-    ecs_term_t *term = &it->terms[term_index - 1];
-    ecs_check(term != NULL, ECS_INVALID_PARAMETER, NULL);
-    
     if (term->inout == EcsIn) {
         return true;
-    } else {
-        ecs_term_id_t *src = &term->src;
-
-        if (term->inout == EcsInOutDefault) {
-            if (!(ecs_term_match_this(term))) {
-                return true;
-            }
+    } else if (term->inout == EcsInOutDefault) {
+        if (!ecs_term_match_this(term)) {
+            return true;
+        }
 
-            if (!(src->flags & EcsSelf)) {
-                return true;
-            }
+        ecs_term_id_t *src = &term->src;
+        if (!(src->flags & EcsSelf)) {
+            return true;
         }
     }
-
 error:
     return false;
 }
 
 bool ecs_field_is_writeonly(
     const ecs_iter_t *it,
-    int32_t term_index)
+    int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-    ecs_check(term_index > 0, ECS_INVALID_PARAMETER, NULL);
-
-    ecs_term_t *term = &it->terms[term_index - 1];
-    ecs_check(term != NULL, ECS_INVALID_PARAMETER, NULL);
-    
-    if (term->inout == EcsOut) {
-        return true;
-    }
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    ecs_term_t *term = &it->terms[index - 1];
+    return term->inout == EcsOut;
 error:
     return false;
 }
@@ -419,7 +404,7 @@ bool ecs_field_is_set(
     int32_t index)
 {
     ecs_check(it->flags & EcsIterIsValid, ECS_INVALID_PARAMETER, NULL);
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     int32_t column = it->columns[index - 1];
     if (!column) {
         return false;
@@ -432,7 +417,6 @@ bool ecs_field_is_set(
             return true;
         }
     }
-
     return true;
 error:
     return false;
@@ -442,8 +426,7 @@ bool ecs_field_is_self(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     return it->sources == NULL || it->sources[index - 1] == 0;
 }
 
@@ -451,8 +434,7 @@ ecs_id_t ecs_field_id(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     return it->ids[index - 1];
 }
 
@@ -460,23 +442,20 @@ int32_t ecs_field_column_index(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
-
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     int32_t result = it->columns[index - 1];
     if (result <= 0) {
         return -1;
+    } else {
+        return result - 1;
     }
-
-    return result - 1;
 }
 
 ecs_entity_t ecs_field_src(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
     if (it->sources) {
         return it->sources[index - 1];
     } else {
@@ -488,14 +467,8 @@ size_t ecs_field_size(
     const ecs_iter_t *it,
     int32_t index)
 {
-    ecs_assert(it != NULL, ECS_INVALID_PARAMETER, NULL);
-    ecs_assert(index >= 0, ECS_INVALID_PARAMETER, NULL);
-
-    if (index == 0) {
-        return sizeof(ecs_entity_t);
-    } else {
-        return (size_t)it->sizes[index - 1];
-    }
+    ecs_assert(index >= 1, ECS_INVALID_PARAMETER, NULL);
+    return (size_t)it->sizes[index - 1];
 }
 
 char* ecs_iter_str(