From 2d2c6aa3739d158560f2cafd0b5d75e3ff6b7609 Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sat, 18 Feb 2023 12:24:39 +0900
Subject: [PATCH] Remove strvar_len

The length limit of string variables was removed a long time ago, but it
was recorded in save files.

Now the first argument of MZ0 is completely ignored (as in System3.9).
The maxlen field in the save file is set to a constant so that older
versions of xsystem35 can load it.
---
 src/cmdm.c     |  7 ++-----
 src/savedata.c | 41 +++++++++++++++++++++++------------------
 src/savedata.h |  2 --
 src/variable.c |  9 +++------
 src/variable.h |  3 +--
 5 files changed, 29 insertions(+), 33 deletions(-)

diff --git a/src/cmdm.c b/src/cmdm.c
index eba8ac5..6d5ebbf 100644
--- a/src/cmdm.c
+++ b/src/cmdm.c
@@ -249,16 +249,13 @@ void commandMF() {
 
 void commandMZ0() {
 	/* 文字列変数の文字数・個数の設定の変更 */
-	int max_len = getCaliValue();
+	int max_len = getCaliValue();  // deprecated in System3.9
 	int max_num = getCaliValue();
 	int rsv     = getCaliValue();
 	
 	DEBUG_COMMAND("MZ0 %d,%d,%d:",max_len, max_num, rsv);
 	
-	/* いつからか、文字列変数の最大長さは∞になったようだ */
-	if (max_len == 0) max_len = STRVAR_LEN * 2;
-	
-	svar_init(max_num, max_len * 2 + 1);
+	svar_init(max_num);
 }
 
 void commandMG() {
diff --git a/src/savedata.c b/src/savedata.c
index 984a23c..6207986 100644
--- a/src/savedata.c
+++ b/src/savedata.c
@@ -572,24 +572,30 @@ static void loadStackInfo(char *buf) {
 
 /* 文字列変数のセーブ */
 static void *saveStrVar(Ald_strVarHdr *head) {
-	int i;
-	char *tmp, *_tmp;
-	_tmp = tmp = malloc(svar_maxindex() * strvar_len);
-	if (tmp == NULL) {
-		WARNING("Out of memory");
-		return NULL;
-	}
-	*tmp = 0;
+	int bufsize = 65536;
+	char *buf = malloc(bufsize);
+	if (!buf)
+		NOMEMERR();
+
+	int offset = 0;
 	// Do not save svar[0], for backward compatibility.
-	for (i = 1; i <= svar_maxindex(); i++) {
-		strncpy(tmp, svar_get(i), strvar_len - 1);
-		tmp[strvar_len - 1] = '\0';
-		tmp += strlen(tmp) + 1;
+	for (int i = 1; i <= svar_maxindex(); i++) {
+		const char *s = svar_get(i);
+		int len = strlen(s);
+		if (offset + len + 1 > bufsize) {
+			bufsize *= 2;
+			buf = realloc(buf, bufsize);
+			if (!buf)
+				NOMEMERR();
+		}
+		strcpy(buf + offset, s);
+		buf[offset + len] = '\0';
+		offset += len + 1;
 	}
-	head->size   = tmp - _tmp;
+	head->size   = offset;
 	head->count  = svar_maxindex();
-	head->maxlen = strvar_len;
-	return _tmp;
+	head->maxlen = 101;  // so that old versions of xystem35 can read this save file
+	return buf;
 }
 
 /* 文字列変数のロード */
@@ -598,10 +604,9 @@ static void loadStrVar(char *buf) {
 	int cnt, max, i;
 	
 	cnt = head->count;
-	max = head->maxlen;
-	if (svar_maxindex() != cnt || strvar_len != max) {
+	if (svar_maxindex() != cnt) {
 		WARNING("Unexpected number of strings in savedata (%d, expected %d)", cnt, svar_maxindex());
-		svar_init(cnt, max);
+		svar_init(cnt);
 	}
 	buf += sizeof(Ald_strVarHdr);
 	for (i = 1; i <= cnt; i++) {
diff --git a/src/savedata.h b/src/savedata.h
index e2aa75b..01fbf34 100644
--- a/src/savedata.h
+++ b/src/savedata.h
@@ -36,8 +36,6 @@
 #define SAVE_SAVEOK1      1
 #define SAVE_SAVEOK0      0
 
-/* defined by variable.c */
-extern int  strvar_len;
 struct VarRef;
 
 int save_loadAll(int no);
diff --git a/src/variable.c b/src/variable.c
index e70653b..e34c8e3 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -48,9 +48,7 @@ struct VarPage varPage[PAGE_MAX];
 double longVar[SYSVARLONG_MAX];
 /* 文字列変数 */
 static char **strVar;
-/* 文字列変数の属性(最大,1つあたりの大きさ) */
-int strvar_cnt;
-int strvar_len;
+static int strvar_cnt;
 
 const char *v_name(int var) {
 	if (var < nact->ain.varnum)
@@ -154,7 +152,7 @@ void v_getPageStatus(int page, int *in_use, int *size) {
 }
 
 /* 文字列変数の再初期化 */
-void svar_init(int max_index, int len) {
+void svar_init(int max_index) {
 	for (int i = max_index + 1; i < strvar_cnt; i++) {
 		if (strVar[i])
 			free(strVar[i]);
@@ -166,7 +164,6 @@ void svar_init(int max_index, int len) {
 	for (int i = strvar_cnt; i <= max_index; i++)
 		strVar[i] = NULL;
 	strvar_cnt = max_index + 1;
-	strvar_len = len;
 }
 
 int svar_maxindex(void) {
@@ -178,7 +175,7 @@ void v_init(void) {
 	varPage[0].value = sysVar;
 	varPage[0].size = SYSVAR_MAX;
 	varPage[0].saveflag = true;
-	svar_init(STRVAR_MAX - 1, STRVAR_LEN);
+	svar_init(STRVAR_MAX - 1);
 }
 
 void v_reset(void) {
diff --git a/src/variable.h b/src/variable.h
index 2d43154..45a4375 100644
--- a/src/variable.h
+++ b/src/variable.h
@@ -29,7 +29,6 @@
 
 #define SYSVAR_MAX       65536
 #define STRVAR_MAX       5000
-#define STRVAR_LEN       101
 
 struct VarPage {
 	int size;
@@ -67,7 +66,7 @@ static inline int *v_ref(int var, struct VarRef *ref) {
 	return v_ref_indexed(var, -1, ref);
 }
 
-void svar_init(int max_index, int len);
+void svar_init(int max_index);
 int svar_maxindex(void);
 const char *svar_get(int no);
 void svar_set(int no, const char *str);