From efae1e913ddd8b81376454dea12803905ee84f6a Mon Sep 17 00:00:00 2001
From: Mark Nudelman <markn@greenwoodsoftware.com>
Date: Mon, 6 Nov 2023 23:26:30 -0800
Subject: [PATCH] Constify.

---
 charset.c  | 12 ++++++------
 cmdbuf.c   | 19 ++++++++++---------
 command.c  |  2 +-
 decode.c   | 21 +++++++++++----------
 filename.c | 10 +++++-----
 line.c     |  4 ++--
 main.c     |  6 +++---
 opttbl.c   |  2 +-
 prompt.c   |  4 ++--
 screen.c   | 49 +++++++++++++++++++++++++------------------------
 tags.c     |  2 +-
 11 files changed, 67 insertions(+), 64 deletions(-)

diff --git a/charset.c b/charset.c
index b9f984e4..2825a68f 100644
--- a/charset.c
+++ b/charset.c
@@ -145,7 +145,7 @@ static void wchar_range_table_set(struct wchar_range_table *tbl, struct xbuffer
 /*
  * Skip over a "U" or "U+" prefix before a hex codepoint.
  */
-static char * skip_uprefix(char *s)
+static constant char * skip_uprefix(constant char *s)
 {
 	if (*s == 'U' || *s == 'u')
 		if (*++s == '+') ++s;
@@ -155,14 +155,14 @@ static char * skip_uprefix(char *s)
 /*
  * Parse a dash-separated range of hex values.
  */
-static void wchar_range_get(char **ss, struct wchar_range *range)
+static void wchar_range_get(constant char **ss, struct wchar_range *range)
 {
-	char *s = skip_uprefix(*ss);
-	range->first = lstrtoul(s, &s, 16);
+	constant char *s = skip_uprefix(*ss);
+	range->first = lstrtoulc(s, &s, 16);
 	if (s[0] == '-')
 	{
 		s = skip_uprefix(&s[1]);
-		range->last = lstrtoul(s, &s, 16);
+		range->last = lstrtoulc(s, &s, 16);
 	} else 
 	{
 		range->last = range->first;
@@ -173,7 +173,7 @@ static void wchar_range_get(char **ss, struct wchar_range *range)
 /*
  * Parse the LESSUTFCHARDEF variable.
  */
-static void ichardef_utf(char *s)
+static void ichardef_utf(constant char *s)
 {
 	xbuf_init(&user_wide_array);
 	xbuf_init(&user_ubin_array);
diff --git a/cmdbuf.c b/cmdbuf.c
index 45787b8b..3e8961ce 100644
--- a/cmdbuf.c
+++ b/cmdbuf.c
@@ -1093,7 +1093,7 @@ static char * next_compl(int action, char *prev)
  */
 static int cmd_complete(int action)
 {
-	char *s;
+	constant char *s;
 
 	if (!in_completion || action == EC_EXPAND)
 	{
@@ -1344,7 +1344,7 @@ static int mlist_size(struct mlist *ml)
  */
 static char * histfile_find(int must_exist)
 {
-	char *home = lgetenv("HOME");
+	constant char *home = lgetenv("HOME");
 	char *name = NULL;
 
 	/* Try in $XDG_STATE_HOME, then in $HOME/.local/state, then in $XDG_DATA_HOME, then in $HOME. */
@@ -1371,7 +1371,8 @@ static char * histfile_find(int must_exist)
 
 static char * histfile_name(int must_exist)
 {
-	char *name;
+	constant char *name;
+	char *wname;
 
 	/* See if filename is explicitly specified by $LESSHISTFILE. */
 	name = lgetenv("LESSHISTFILE");
@@ -1387,15 +1388,15 @@ static char * histfile_name(int must_exist)
 	if (strcmp(LESSHISTFILE, "") == 0 || strcmp(LESSHISTFILE, "-") == 0)
 		return (NULL);
 
-	name = NULL;
+	wname = NULL;
 	if (!must_exist)
 	{
 	 	/* If we're writing the file and the file already exists, use it. */
-		name = histfile_find(1);
+		wname = histfile_find(1);
 	}
-	if (name == NULL)
-		name = histfile_find(must_exist);
-	return (name);
+	if (wname == NULL)
+		wname = histfile_find(must_exist);
+	return (wname);
 }
 
 /*
@@ -1632,7 +1633,7 @@ public void save_cmdhist(void)
 	int skip_search;
 	int skip_shell;
 	struct save_ctx ctx;
-	char *s;
+	constant char *s;
 	FILE *fout = NULL;
 	int histsize = 0;
 
diff --git a/command.c b/command.c
index 6091666e..57a9fa55 100644
--- a/command.c
+++ b/command.c
@@ -51,7 +51,7 @@ extern int updown_match;
 extern void *ml_shell;
 #endif
 #if EDITOR
-extern char *editproto;
+extern constant char *editproto;
 #endif
 extern int shift_count;
 extern int forw_prompt;
diff --git a/decode.c b/decode.c
index 95e87640..ef86a6e8 100644
--- a/decode.c
+++ b/decode.c
@@ -738,29 +738,29 @@ public int ecmd_decode(constant char *cmd, constant char **sp)
  * Get the value of an environment variable.
  * Looks first in the lesskey file, then in the real environment.
  */
-public char * lgetenv(constant char *var) /*{{const-issue}}*/
+public constant char * lgetenv(constant char *var)
 {
 	int a;
 	constant char *s;
 
 	a = cmd_decode(list_var_tables, var, &s);
 	if (a == EV_OK)
-		return ((char *) s);  /*{{const-issue}}*/
+		return (s);  /*{{const-issue}}*/
 	s = getenv(var);
 	if (s != NULL && *s != '\0')
-		return ((char *) s);  /*{{const-issue}}*/
+		return (s);  /*{{const-issue}}*/
 	a = cmd_decode(list_sysvar_tables, var, &s);
 	if (a == EV_OK)
-		return ((char *) s);  /*{{const-issue}}*/
+		return (s);  /*{{const-issue}}*/
 	return (NULL);
 }
 
 /*
  * Like lgetenv, but also uses a buffer partially filled with an env table.
  */
-public char * lgetenv_ext(constant char *var, unsigned char *env_buf, int env_buf_len)
+public constant char * lgetenv_ext(constant char *var, unsigned char *env_buf, int env_buf_len)
 {
-	char *r;
+	constant char *r;
 	int e;
 	int env_end = 0;
 
@@ -992,21 +992,22 @@ void lesskey_parse_error(char *s)
 public int add_hometable(int (*call_lesskey)(constant char *, int), char *envname, char *def_filename, int sysvar)
 {
 	char *filename;
+	constant char *efilename;
 	int r;
 
-	if (envname != NULL && (filename = lgetenv(envname)) != NULL)
-		filename = save(filename);
+	if (envname != NULL && (efilename = lgetenv(envname)) != NULL)
+		filename = save(efilename);
 	else if (sysvar) /* def_filename is full path */
 		filename = save(def_filename);
 	else /* def_filename is just basename */
 	{
 		/* Remove first char (normally a dot) unless stored in $HOME. */
-		char *xdg = lgetenv("XDG_CONFIG_HOME");
+		constant char *xdg = lgetenv("XDG_CONFIG_HOME");
 		if (!isnullenv(xdg))
 			filename = dirfile(xdg, &def_filename[1], 1);
 		if (filename == NULL)
 		{
-			char *home = lgetenv("HOME");
+			constant char *home = lgetenv("HOME");
 			if (!isnullenv(home))
 			{
 				char *cfg_dir = dirfile(home, ".config", 0);
diff --git a/filename.c b/filename.c
index 8c55c568..8ac67b09 100644
--- a/filename.c
+++ b/filename.c
@@ -100,7 +100,7 @@ public char * shell_unquote(constant char *str)
  */
 public constant char * get_meta_escape(void)
 {
-	char *s;
+	constant char *s;
 
 	s = lgetenv("LESSMETAESCAPE");
 	if (s == NULL)
@@ -113,7 +113,7 @@ public constant char * get_meta_escape(void)
  */
 static constant char * metachars(void)
 {
-	static char *mchars = NULL;
+	static constant char *mchars = NULL;
 
 	if (mchars == NULL)
 	{
@@ -551,7 +551,7 @@ static FILE * shellcmd(constant char *cmd)
 	FILE *fd;
 
 #if HAVE_SHELL
-	char *shell;
+	constant char *shell;
 
 	shell = lgetenv("SHELL");
 	if (!isnullenv(shell))
@@ -833,7 +833,7 @@ public char * open_altfile(constant char *filename, int *pf, void **pfd)
 #if !HAVE_POPEN
 	return (NULL);
 #else
-	char *lessopen;
+	constant char *lessopen;
 	char *qfilename;
 	char *cmd;
 	int len;
@@ -954,7 +954,7 @@ public char * open_altfile(constant char *filename, int *pf, void **pfd)
 public void close_altfile(constant char *altfilename, constant char *filename)
 {
 #if HAVE_POPEN
-	char *lessclose;
+	constant char *lessclose;
 	char *qfilename;
 	char *qaltfilename;
 	FILE *fd;
diff --git a/line.c b/line.c
index e9f7dff1..00db5fdd 100644
--- a/line.c
+++ b/line.c
@@ -71,8 +71,8 @@ static int last_overstrike = AT_NORMAL;
 static int is_null_line;  /* There is no current line */
 static LWCHAR pendc;
 static POSITION pendpos;
-static char *end_ansi_chars;
-static char *mid_ansi_chars;
+static constant char *end_ansi_chars;
+static constant char *mid_ansi_chars;
 static int in_hilite;
 
 static int attr_swidth(int a);
diff --git a/main.c b/main.c
index ec4b680d..9091ce07 100644
--- a/main.c
+++ b/main.c
@@ -46,8 +46,8 @@ public char *   namelogfile = NULL;
 #endif
 
 #if EDITOR
-public char *   editor;
-public char *   editproto;
+public constant char *   editor;
+public constant char *   editproto;
 #endif
 
 #if TAGS
@@ -233,7 +233,7 @@ static void init_secure(void)
 int main(int argc, char *argv[])
 {
 	IFILE ifile;
-	char *s;
+	constant char *s;
 
 #if MSDOS_COMPILER==WIN32C && (defined(MINGW) || defined(_MSC_VER))
 	if (GetACP() != CP_UTF8)  /* not using a UTF-8 manifest */
diff --git a/opttbl.c b/opttbl.c
index b21f1549..e1c9bf1f 100644
--- a/opttbl.c
+++ b/opttbl.c
@@ -744,7 +744,7 @@ static struct loption option[] =
 public void init_option(void)
 {
 	struct loption *o;
-	char *p;
+	constant char *p;
 
 	p = lgetenv("LESS_IS_MORE");
 	if (!isnullenv(p))
diff --git a/prompt.c b/prompt.c
index a827ba72..5835fca2 100644
--- a/prompt.c
+++ b/prompt.c
@@ -30,8 +30,8 @@ extern int less_is_more;
 extern int header_lines;
 extern IFILE curr_ifile;
 #if EDITOR
-extern char *editor;
-extern char *editproto;
+extern constant char *editor;
+extern constant char *editproto;
 #endif
 
 /*
diff --git a/screen.c b/screen.c
index 17401ac5..a8276b9b 100644
--- a/screen.c
+++ b/screen.c
@@ -190,7 +190,7 @@ public int vt_enabled = -1;     /* Is virtual terminal processing available? */
 /*
  * Strings passed to tputs() to do various terminal functions.
  */
-static char
+static constant char
 	*sc_pad,                /* Pad string */
 	*sc_home,               /* Cursor home */
 	*sc_addline,            /* Add line, scroll down following lines */
@@ -237,7 +237,7 @@ public int above_mem, below_mem;        /* Memory retained above/below screen */
 public int can_goto_line;               /* Can move cursor to any line */
 public int clear_bg;            /* Clear fills with background color */
 public int missing_cap = 0;     /* Some capability is missing */
-public char *kent = NULL;       /* Keypad ENTER sequence */
+public constant char *kent = NULL;       /* Keypad ENTER sequence */
 public int term_init_done = FALSE;
 public int full_screen = TRUE;
 
@@ -251,9 +251,9 @@ extern char *ttyin_name;
 #endif /*LESSTEST*/
 
 #if !MSDOS_COMPILER
-static char *cheaper(char *t1, char *t2, char *def);
-static void tmodes(char *incap, char *outcap, char **instr,
-    char **outstr, char *def_instr, char *def_outstr, char **spp);
+static constant char *cheaper(constant char *t1, constant char *t2, constant char *def);
+static void tmodes(constant char *incap, constant char *outcap, constant char **instr,
+    constant char **outstr, constant char *def_instr, constant char *def_outstr, char **spp);
 #endif
 
 /*
@@ -706,7 +706,7 @@ public void raw_mode(int on)
  */
 static int hardcopy;
 
-static char * ltget_env(char *capname)
+static constant char * ltget_env(constant char *capname)
 {
 	char name[64];
 
@@ -732,7 +732,7 @@ static char * ltget_env(char *capname)
 
 static int ltgetflag(char *capname)
 {
-	char *s;
+	constant char *s;
 
 	if ((s = ltget_env(capname)) != NULL)
 		return (*s != '\0' && *s != '0');
@@ -743,7 +743,7 @@ static int ltgetflag(char *capname)
 
 static int ltgetnum(char *capname)
 {
-	char *s;
+	constant char *s;
 
 	if ((s = ltget_env(capname)) != NULL)
 		return (atoi(s));
@@ -752,9 +752,9 @@ static int ltgetnum(char *capname)
 	return (tgetnum(capname));
 }
 
-static char * ltgetstr(char *capname, char **pp)
+static constant char * ltgetstr(constant char *capname, char **pp)
 {
-	char *s;
+	constant char *s;
 
 	if ((s = ltget_env(capname)) != NULL)
 		return (s);
@@ -769,7 +769,7 @@ static char * ltgetstr(char *capname, char **pp)
  */
 static void scrsize(void)
 {
-	char *s;
+	constant char *s;
 	int sys_height;
 	int sys_width;
 #if !MSDOS_COMPILER
@@ -958,7 +958,7 @@ static void delay(int msec)
 public constant char * special_key_str(int key)
 {
 	static char tbuf[40];
-	char *s;
+	constant char *s;
 #if MSDOS_COMPILER || OS2
 	static char k_right[]           = { '\340', PCK_RIGHT, 0 };
 	static char k_left[]            = { '\340', PCK_LEFT, 0  };
@@ -1201,8 +1201,9 @@ public void get_term(void)
 #else /* !MSDOS_COMPILER */
 {
 	char *sp;
-	char *t1, *t2;
-	char *term;
+	constant char *t1;
+	constant char *t2;
+	constant char *term;
 	/*
 	 * Some termcap libraries assume termbuf is static
 	 * (accessible after tgetent returns).
@@ -1214,8 +1215,8 @@ public void get_term(void)
 	/*
 	 * Make sure the termcap database is available.
 	 */
-	sp = lgetenv("TERMCAP");
-	if (isnullenv(sp))
+	constant char *cp = lgetenv("TERMCAP");
+	if (isnullenv(cp))
 	{
 		char *termcap;
 		if ((sp = homefile("termcap.dat")) != NULL)
@@ -1452,7 +1453,7 @@ static int inc_costcount(int c)
 	return (c);
 }
 
-static int cost(char *t)
+static int cost(constant char *t)
 {
 	costcount = 0;
 	tputs(t, sc_height, inc_costcount);
@@ -1464,7 +1465,7 @@ static int cost(char *t)
  * The best, if both exist, is the one with the lower 
  * cost (see cost() function).
  */
-static char * cheaper(char *t1, char *t2, char *def)
+static constant char * cheaper(constant char *t1, constant char *t2, constant char *def)
 {
 	if (*t1 == '\0' && *t2 == '\0')
 	{
@@ -1480,7 +1481,7 @@ static char * cheaper(char *t1, char *t2, char *def)
 	return (t2);
 }
 
-static void tmodes(char *incap, char *outcap, char **instr, char **outstr, char *def_instr, char *def_outstr, char **spp)
+static void tmodes(constant char *incap, constant char *outcap, constant char **instr, constant char **outstr, constant char *def_instr, constant char *def_outstr, char **spp)
 {
 	*instr = ltgetstr(incap, spp);
 	if (*instr == NULL)
@@ -1634,7 +1635,7 @@ static void win32_deinit_term(void)
 #endif
 
 #if !MSDOS_COMPILER
-static void do_tputs(char *str, int affcnt, int (*f_putc)(int))
+static void do_tputs(constant char *str, int affcnt, int (*f_putc)(int))
 {
 #if LESSTEST
 	if (ttyin_name != NULL && f_putc == putchr)
@@ -1648,7 +1649,7 @@ static void do_tputs(char *str, int affcnt, int (*f_putc)(int))
  * Like tputs but we handle $<...> delay strings here because
  * some implementations of tputs don't perform delays correctly.
  */
-static void ltputs(char *str, int affcnt, int (*f_putc)(int))
+static void ltputs(constant char *str, int affcnt, int (*f_putc)(int))
 {
 	while (str != NULL && *str != '\0')
 	{
@@ -1667,7 +1668,7 @@ static void ltputs(char *str, int affcnt, int (*f_putc)(int))
 				do_tputs(str2, affcnt, f_putc);
 				str += slen + 2;
 				/* Perform the delay. */
-				delay = lstrtoi(str, &str, 10);
+				delay = lstrtoic(str, &str, 10);
 				if (*str == '*')
 					if (ckd_mul(&delay, delay, affcnt))
 						delay = INT_MAX;
@@ -2574,7 +2575,7 @@ static void tput_color(constant char *str, int (*f_putc)(int))
 	}
 }
 
-static void tput_inmode(char *mode_str, int attr, int attr_bit, int (*f_putc)(int))
+static void tput_inmode(constant char *mode_str, int attr, int attr_bit, int (*f_putc)(int))
 {
 	constant char *color_str;
 	if ((attr & attr_bit) == 0)
@@ -2590,7 +2591,7 @@ static void tput_inmode(char *mode_str, int attr, int attr_bit, int (*f_putc)(in
 	tput_color(color_str, f_putc);
 }
 
-static void tput_outmode(char *mode_str, int attr_bit, int (*f_putc)(int))
+static void tput_outmode(constant char *mode_str, int attr_bit, int (*f_putc)(int))
 {
 	if ((attrmode & attr_bit) == 0)
 		return;
diff --git a/tags.c b/tags.c
index 41f6f220..e7dead46 100644
--- a/tags.c
+++ b/tags.c
@@ -510,7 +510,7 @@ static enum tag_result findgtag(char *tag, int type)
 		char *command;
 		char *flag;
 		char *qtag;
-		char *cmd = lgetenv("LESSGLOBALTAGS");
+		constant char *cmd = lgetenv("LESSGLOBALTAGS");
 
 		if (isnullenv(cmd))
 			return TAG_NOFILE;