thanm: fix negative script id recompiling

Turns out that instructions don't refer to scripts by their ID, but by their index in the file, which is not always the same.

Why.

thanm/anmparse.y

@@ -434,9 +434,10 @@ Script:
         reg_reset(state->current_version);
         script->offset = malloc(sizeof(*script->offset));
         script->offset->id = state->script_id++;
+        script->real_index = state->script_real_index++;
 
         symbol_id_pair_t* symbol = (symbol_id_pair_t*)malloc(sizeof(symbol_id_pair_t));
-        symbol->id = script->offset->id;
+        symbol->id = script->real_index;
         symbol->name = $name;
         list_append_new(&state->script_names, symbol);
         if (state->symbolfp != NULL)

thanm/thanm.c

@@ -657,34 +657,55 @@ replace_minus(
     }
 }
 
+static int
+anm_is_valid_script_index(
+    const anm_archive_t* anm,
+    int32_t index
+) {
+    anm_entry_t* entry;
+    anm_script_t* script;
+    list_for_each(&anm->entries, entry) {
+        list_for_each(&entry->scripts, script) {
+            if (script->real_index == index)
+                return 1;
+        }
+    }
+    return 0;
+}
+
 static void
 anm_stringify_param(
     FILE* stream,
     thanm_param_t* param,
     thanm_instr_t* instr,
-    int scriptn
+    const anm_archive_t* anm,
+    int32_t scriptn
 ) {
     char* disp = NULL;
     char* dest = NULL;
     char buf[256];
 
     switch(param->type) {
         case 'o':
-            sprintf(buf, "offset%u", param->val->val.S);
+            sprintf(buf, "offset%d", param->val->val.S);
             replace_minus(buf);
             dest = buf;
             break;
         case 'n':
-            /* Sprite -1 is used as an empty sprite. */
-            if (param->val->val.S == -1)
+            /* Sprite -1 is actually sometimes used to indicate no sprite. */
+            if (param->val->val.S < 0)
                 sprintf(buf, "%d", param->val->val.S);
             else
                 sprintf(buf, "sprite%d", param->val->val.S);
             dest = buf;
             break;
         case 'N':
-            sprintf(buf, "script%d", param->val->val.S);
-            replace_minus(buf);
+            if (anm_is_valid_script_index(anm, param->val->val.S)) {
+                sprintf(buf, "script%d", param->val->val.S);
+                replace_minus(buf);
+            } else {
+                sprintf(buf, "%d", param->val->val.S);
+            }
             dest = buf;
             break;
         default:
@@ -811,7 +832,7 @@ thanm_instr_free(
 static void
 anm_insert_labels(
     anm_script_t* script,
-    int scriptn
+    int32_t scriptn
 ) {
     thanm_instr_t* instr;
     list_for_each(&script->instrs, instr) {
@@ -870,7 +891,7 @@ anm_read_file(
     archive->map = map_base = file_mmap(in, file_size);
     map = map_base;
 
-    int scriptn = 0;
+    int32_t scriptn = 0;
     for (;;) {
         anm_entry_t* entry = malloc(sizeof(*entry));
         anm_header06_t* header = (anm_header06_t*)map;
@@ -927,6 +948,7 @@ anm_read_file(
                 (anm_offset_t*)(map + sizeof(*header) + header->sprites * sizeof(uint32_t));
             for (uint32_t s = 0; s < header->scripts; ++s) {
                 anm_script_t* script = anm_script_new();
+                script->real_index = scriptn;
                 script->offset = &(script_offsets[s]);
 
                 unsigned char* limit = map;
@@ -1106,7 +1128,8 @@ static void
 anm_stringify_instr(
     FILE* stream,
     thanm_instr_t* instr,
-    int scriptn
+    const anm_archive_t* anm,
+    int32_t scriptn
 ) {
     seqmap_entry_t* ent = seqmap_get(g_anmmap->ins_names, instr->id);
 
@@ -1117,7 +1140,7 @@ anm_stringify_instr(
 
     thanm_param_t* param;
     list_for_each(&instr->params, param) {
-        anm_stringify_param(stream, param, instr, scriptn);
+        anm_stringify_param(stream, param, instr, anm, scriptn);
         if (!list_is_last_iteration()) {
             fprintf(stream, ", ");
         }
@@ -1135,7 +1158,6 @@ anm_dump(
     unsigned int entry_num = 0;
     anm_entry_t* entry;
 
-    int scriptn = 0;
     int prev_sprite_id = -1;
     int prev_script_id = -1;
     list_for_each(&anm->entries, entry) {
@@ -1198,13 +1220,17 @@ anm_dump(
 
         anm_script_t* script;
         list_for_each(&entry->scripts, script) {
-
-            sprintf(buf, "script%d", script->offset->id);
-            replace_minus(buf);
+            /* We need to use the index of the script in file for the name, because that's
+             * what instructions that refer to scripts use. I'm unsure what's the actual purpose of the ID field.
+             * However! I still don't really know how old versions work, and maybe instructions refer to the
+             * ID field there? If that's the case, it should be enough to just do a check earlier that sets
+             * real_index to offset->id in old versions (and re-add the replace_minus calls).
+             * I honestly doubt that this is the case, but I want to leave a note how to change it anyway in case
+             * it's needed... */
             if (script->offset->id - 1 != prev_script_id) {
-                fprintf(stream, "script %d %s {\n", script->offset->id, buf);
+                fprintf(stream, "script %d script%d {\n", script->offset->id, script->real_index);
             } else {
-                fprintf(stream, "script %s {\n", buf);
+                fprintf(stream, "script script%d {\n", script->real_index);
             }
             prev_script_id = script->offset->id;
 
@@ -1215,7 +1241,7 @@ anm_dump(
                 switch(instr->type) {
                     case THANM_INSTR_INSTR:
                         fprintf(stream, "    ");
-                        anm_stringify_instr(stream, instr, scriptn);
+                        anm_stringify_instr(stream, instr, anm, script->real_index);
                         break;
                     case THANM_INSTR_TIME:
                         if (instr->time < 0)
@@ -1240,7 +1266,6 @@ anm_dump(
             }
 
             fprintf(stream, "}\n\n");
-            ++scriptn;
         }
 
         fprintf(stream, "\n");
@@ -1755,6 +1780,7 @@ anm_create(
     state.current_version = -1;
     state.sprite_id = 0;
     state.script_id = 0;
+    state.script_real_index = 0;
     list_init(&state.entries);
     list_init(&state.globals);
     list_init(&state.script_names);

thanm/thanm.h

@@ -42,6 +42,8 @@ extern unsigned int option_force;
 const id_format_pair_t* anm_get_formats(uint32_t version);
 
 typedef struct {
+    /* The id in the offset struct may not be the real index. */
+    int32_t real_index;
     anm_offset_t* offset;
     /* instrs of thanm_instr_t format */
     list_t instrs;
@@ -125,7 +127,8 @@ typedef struct parser_state_t {
     int32_t current_version;
     uint32_t offset;
     uint32_t sprite_id;
-    uint32_t script_id;
+    int32_t script_id;
+    int32_t script_real_index;
     /* List of anm_entry_t */
     list_t entries;
     anm_entry_t* current_entry;