'lua.h' back to redundancy in version definitions

Several tools inspect 'lua.h' to extract version information, and
they assume the file will have some specific format.

lauxlib.c

@@ -80,6 +80,7 @@ static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
   int top = lua_gettop(L);
   lua_getinfo(L, "f", ar);  /* push function */
   lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
+  luaL_checkstack(L, 6, "not enough stack");  /* slots for 'findfield' */
   if (findfield(L, top + 1, 2)) {
     const char *name = lua_tostring(L, -1);
     if (strncmp(name, LUA_GNAME ".", 3) == 0) {  /* name start with '_G.'? */
@@ -249,11 +250,13 @@ LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
     return 1;
   }
   else {
+    const char *msg;
     luaL_pushfail(L);
+    msg = (en != 0) ? strerror(en) : "(no extra info)";
     if (fname)
-      lua_pushfstring(L, "%s: %s", fname, strerror(en));
+      lua_pushfstring(L, "%s: %s", fname, msg);
     else
-      lua_pushstring(L, strerror(en));
+      lua_pushstring(L, msg);
     lua_pushinteger(L, en);
     return 3;
   }
@@ -732,9 +735,12 @@ static const char *getF (lua_State *L, void *ud, size_t *size) {
 
 
 static int errfile (lua_State *L, const char *what, int fnameindex) {
-  const char *serr = strerror(errno);
+  int err = errno;
   const char *filename = lua_tostring(L, fnameindex) + 1;
-  lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
+  if (err != 0)
+    lua_pushfstring(L, "cannot %s %s: %s", what, filename, strerror(err));
+  else
+    lua_pushfstring(L, "cannot %s %s", what, filename);
   lua_remove(L, fnameindex);
   return LUA_ERRFILE;
 }
@@ -787,6 +793,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   }
   else {
     lua_pushfstring(L, "@%s", filename);
+    errno = 0;
     lf.f = fopen(filename, "r");
     if (lf.f == NULL) return errfile(L, "open", fnameindex);
   }
@@ -796,6 +803,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   if (c == LUA_SIGNATURE[0]) {  /* binary file? */
     lf.n = 0;  /* remove possible newline */
     if (filename) {  /* "real" file? */
+      errno = 0;
       lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
       if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
       skipcomment(lf.f, &c);  /* re-read initial portion */
@@ -803,6 +811,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   }
   if (c != EOF)
     lf.buff[lf.n++] = c;  /* 'c' is the first character of the stream */
+  errno = 0;
   status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
   readstatus = ferror(lf.f);
   if (filename) fclose(lf.f);  /* close file (even in case of errors) */
@@ -933,7 +942,7 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
   luaL_checkstack(L, nup, "too many upvalues");
   for (; l->name != NULL; l++) {  /* fill the table with given functions */
-    if (l->func == NULL)  /* place holder? */
+    if (l->func == NULL)  /* placeholder? */
       lua_pushboolean(L, 0);
     else {
       int i;

lcode.c

@@ -776,7 +776,8 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
       break;
     }
     case VLOCAL: {  /* already in a register */
-      e->u.info = e->u.var.ridx;
+      int temp = e->u.var.ridx;
+      e->u.info = temp;  /* (can't do a direct assignment; values overlap) */
       e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
@@ -1283,8 +1284,9 @@ void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
   if (t->k == VUPVAL && !isKstr(fs, k))  /* upvalue indexed by non 'Kstr'? */
     luaK_exp2anyreg(fs, t);  /* put it in a register */
   if (t->k == VUPVAL) {
+    int temp = t->u.info;  /* upvalue index */
     lua_assert(isKstr(fs, k));
-    t->u.ind.t = t->u.info;  /* upvalue index */
+    t->u.ind.t = temp;  /* (can't do a direct assignment; values overlap) */
     t->u.ind.idx = k->u.info;  /* literal short string */
     t->k = VINDEXUP;
   }

ldebug.c

@@ -31,7 +31,7 @@
 
 
 
-#define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_VCCL)
+#define LuaClosure(f)		((f) != NULL && (f)->c.tt == LUA_VLCL)
 
 
 static const char *funcnamefromcall (lua_State *L, CallInfo *ci,
@@ -254,7 +254,7 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
 
 
 static void funcinfo (lua_Debug *ar, Closure *cl) {
-  if (noLuaClosure(cl)) {
+  if (!LuaClosure(cl)) {
     ar->source = "=[C]";
     ar->srclen = LL("=[C]");
     ar->linedefined = -1;
@@ -288,29 +288,31 @@ static int nextline (const Proto *p, int currentline, int pc) {
 
 
 static void collectvalidlines (lua_State *L, Closure *f) {
-  if (noLuaClosure(f)) {
+  if (!LuaClosure(f)) {
     setnilvalue(s2v(L->top.p));
     api_incr_top(L);
   }
   else {
-    int i;
-    TValue v;
     const Proto *p = f->l.p;
     int currentline = p->linedefined;
     Table *t = luaH_new(L);  /* new table to store active lines */
     sethvalue2s(L, L->top.p, t);  /* push it on stack */
     api_incr_top(L);
-    setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
-    if (!p->is_vararg)  /* regular function? */
-      i = 0;  /* consider all instructions */
-    else {  /* vararg function */
-      lua_assert(GET_OPCODE(p->code[0]) == OP_VARARGPREP);
-      currentline = nextline(p, currentline, 0);
-      i = 1;  /* skip first instruction (OP_VARARGPREP) */
-    }
-    for (; i < p->sizelineinfo; i++) {  /* for each instruction */
-      currentline = nextline(p, currentline, i);  /* get its line */
-      luaH_setint(L, t, currentline, &v);  /* table[line] = true */
+    if (p->lineinfo != NULL) {  /* proto with debug information? */
+      int i;
+      TValue v;
+      setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
+      if (!p->is_vararg)  /* regular function? */
+        i = 0;  /* consider all instructions */
+      else {  /* vararg function */
+        lua_assert(GET_OPCODE(p->code[0]) == OP_VARARGPREP);
+        currentline = nextline(p, currentline, 0);
+        i = 1;  /* skip first instruction (OP_VARARGPREP) */
+      }
+      for (; i < p->sizelineinfo; i++) {  /* for each instruction */
+        currentline = nextline(p, currentline, i);  /* get its line */
+        luaH_setint(L, t, currentline, &v);  /* table[line] = true */
+      }
     }
   }
 }
@@ -339,7 +341,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
       }
       case 'u': {
         ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
-        if (noLuaClosure(f)) {
+        if (!LuaClosure(f)) {
           ar->isvararg = 1;
           ar->nparams = 0;
         }

lgc.c

@@ -1713,7 +1713,7 @@ static void fullinc (lua_State *L, global_State *g) {
   /* finish any pending sweep phase to start a new cycle */
   luaC_runtilstate(L, bitmask(GCSpause));
   luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
-  g->gcstate = GCSenteratomic;  /* go straight to atomic phase ??? */
+  g->gcstate = GCSenteratomic;  /* go straight to atomic phase */
   luaC_runtilstate(L, bitmask(GCScallfin));  /* run up to finalizers */
   /* estimate must be correct after a full GC cycle */
   lua_assert(g->GCestimate == gettotalbytes(g));

liolib.c

@@ -245,8 +245,8 @@ static int f_gc (lua_State *L) {
 */
 static int io_fclose (lua_State *L) {
   LStream *p = tolstream(L);
-  int res = fclose(p->f);
-  return luaL_fileresult(L, (res == 0), NULL);
+  errno = 0;
+  return luaL_fileresult(L, (fclose(p->f) == 0), NULL);
 }
 
 
@@ -272,6 +272,7 @@ static int io_open (lua_State *L) {
   LStream *p = newfile(L);
   const char *md = mode;  /* to traverse/check mode */
   luaL_argcheck(L, l_checkmode(md), 2, "invalid mode");
+  errno = 0;
   p->f = fopen(filename, mode);
   return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
 }
@@ -292,6 +293,7 @@ static int io_popen (lua_State *L) {
   const char *mode = luaL_optstring(L, 2, "r");
   LStream *p = newprefile(L);
   luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
+  errno = 0;
   p->f = l_popen(L, filename, mode);
   p->closef = &io_pclose;
   return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
@@ -300,6 +302,7 @@ static int io_popen (lua_State *L) {
 
 static int io_tmpfile (lua_State *L) {
   LStream *p = newfile(L);
+  errno = 0;
   p->f = tmpfile();
   return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
 }
@@ -567,6 +570,7 @@ static int g_read (lua_State *L, FILE *f, int first) {
   int nargs = lua_gettop(L) - 1;
   int n, success;
   clearerr(f);
+  errno = 0;
   if (nargs == 0) {  /* no arguments? */
     success = read_line(L, f, 1);
     n = first + 1;  /* to return 1 result */
@@ -660,6 +664,7 @@ static int io_readline (lua_State *L) {
 static int g_write (lua_State *L, FILE *f, int arg) {
   int nargs = lua_gettop(L) - arg;
   int status = 1;
+  errno = 0;
   for (; nargs--; arg++) {
     if (lua_type(L, arg) == LUA_TNUMBER) {
       /* optimization: could be done exactly as for strings */
@@ -678,7 +683,8 @@ static int g_write (lua_State *L, FILE *f, int arg) {
   }
   if (l_likely(status))
     return 1;  /* file handle already on stack top */
-  else return luaL_fileresult(L, status, NULL);
+  else
+    return luaL_fileresult(L, status, NULL);
 }
 
 
@@ -703,6 +709,7 @@ static int f_seek (lua_State *L) {
   l_seeknum offset = (l_seeknum)p3;
   luaL_argcheck(L, (lua_Integer)offset == p3, 3,
                   "not an integer in proper range");
+  errno = 0;
   op = l_fseek(f, offset, mode[op]);
   if (l_unlikely(op))
     return luaL_fileresult(L, 0, NULL);  /* error */
@@ -719,19 +726,25 @@ static int f_setvbuf (lua_State *L) {
   FILE *f = tofile(L);
   int op = luaL_checkoption(L, 2, NULL, modenames);
   lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
-  int res = setvbuf(f, NULL, mode[op], (size_t)sz);
+  int res;
+  errno = 0;
+  res = setvbuf(f, NULL, mode[op], (size_t)sz);
   return luaL_fileresult(L, res == 0, NULL);
 }
 
 
 
 static int io_flush (lua_State *L) {
-  return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
+  FILE *f = getiofile(L, IO_OUTPUT);
+  errno = 0;
+  return luaL_fileresult(L, fflush(f) == 0, NULL);
 }
 
 
 static int f_flush (lua_State *L) {
-  return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
+  FILE *f = tofile(L);
+  errno = 0;
+  return luaL_fileresult(L, fflush(f) == 0, NULL);
 }
 
 
@@ -773,7 +786,7 @@ static const luaL_Reg meth[] = {
 ** metamethods for file handles
 */
 static const luaL_Reg metameth[] = {
-  {"__index", NULL},  /* place holder */
+  {"__index", NULL},  /* placeholder */
   {"__gc", f_gc},
   {"__close", f_gc},
   {"__tostring", f_tostring},

lmathlib.c

@@ -352,7 +352,7 @@ static lua_Number I2d (Rand64 x) {
   SRand64 sx = (SRand64)(trim64(x) >> shift64_FIG);
   lua_Number res = (lua_Number)(sx) * scaleFIG;
   if (sx < 0)
-    res += 1.0;  /* correct the two's complement if negative */
+    res += l_mathop(1.0);  /* correct the two's complement if negative */
   lua_assert(0 <= res && res < 1);
   return res;
 }

loslib.c

@@ -155,6 +155,7 @@ static int os_execute (lua_State *L) {
 
 static int os_remove (lua_State *L) {
   const char *filename = luaL_checkstring(L, 1);
+  errno = 0;
   return luaL_fileresult(L, remove(filename) == 0, filename);
 }
 
@@ -162,6 +163,7 @@ static int os_remove (lua_State *L) {
 static int os_rename (lua_State *L) {
   const char *fromname = luaL_checkstring(L, 1);
   const char *toname = luaL_checkstring(L, 2);
+  errno = 0;
   return luaL_fileresult(L, rename(fromname, toname) == 0, NULL);
 }
 

ltests.c

@@ -1650,6 +1650,11 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
       int nres;
       status = lua_resume(lua_tothread(L1, i), L, getnum, &nres);
     }
+    else if EQ("traceback") {
+      const char *msg = getstring;
+      int level = getnum;
+      luaL_traceback(L1, L1, msg, level);
+    }
     else if EQ("return") {
       int n = getnum;
       if (L1 != L) {

lua.c

@@ -115,12 +115,13 @@ static void l_message (const char *pname, const char *msg) {
 
 /*
 ** Check whether 'status' is not OK and, if so, prints the error
-** message on the top of the stack. It assumes that the error object
-** is a string, as it was either generated by Lua or by 'msghandler'.
+** message on the top of the stack.
 */
 static int report (lua_State *L, int status) {
   if (status != LUA_OK) {
     const char *msg = lua_tostring(L, -1);
+    if (msg == NULL)
+      msg = "(error message not a string)";
     l_message(progname, msg);
     lua_pop(L, 1);  /* remove message */
   }
@@ -211,7 +212,7 @@ static int dostring (lua_State *L, const char *s, const char *name) {
 /*
 ** Receives 'globname[=modname]' and runs 'globname = require(modname)'.
 ** If there is no explicit modname and globname contains a '-', cut
-** the sufix after '-' (the "version") to make the global name.
+** the suffix after '-' (the "version") to make the global name.
 */
 static int dolibrary (lua_State *L, char *globname) {
   int status;
@@ -230,7 +231,7 @@ static int dolibrary (lua_State *L, char *globname) {
   status = docall(L, 1, 1);  /* call 'require(modname)' */
   if (status == LUA_OK) {
     if (suffix != NULL)  /* is there a suffix mark? */
-      *suffix = '\0';  /* remove sufix from global name */
+      *suffix = '\0';  /* remove suffix from global name */
     lua_setglobal(L, globname);  /* globname = require(modname) */
   }
   return report(L, status);

lua.h

@@ -1,7 +1,7 @@
 /*
 ** $Id: lua.h $
 ** Lua - A Scripting Language
-** Lua.org, PUC-Rio, Brazil (www.lua.org)
+** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
 */
 
@@ -13,21 +13,22 @@
 #include <stddef.h>
 
 
-#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2023 Lua.org, PUC-Rio"
-#define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
-
-
-#define LUA_VERSION_MAJOR_N	5
-#define LUA_VERSION_MINOR_N	4
-#define LUA_VERSION_RELEASE_N	6
-
-#define LUA_VERSION_NUM  (LUA_VERSION_MAJOR_N * 100 + LUA_VERSION_MINOR_N)
-#define LUA_VERSION_RELEASE_NUM  (LUA_VERSION_NUM * 100 + LUA_VERSION_RELEASE_N)
-
-
 #include "luaconf.h"
 
 
+#define LUA_VERSION_MAJOR	"5"
+#define LUA_VERSION_MINOR	"4"
+#define LUA_VERSION_RELEASE	"7"
+
+#define LUA_VERSION_NUM			504
+#define LUA_VERSION_RELEASE_NUM		(LUA_VERSION_NUM * 100 + 7)
+
+#define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
+#define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
+#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2024 Lua.org, PUC-Rio"
+#define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
+
+
 /* mark for precompiled code ('<esc>Lua') */
 #define LUA_SIGNATURE	"\x1bLua"
 
@@ -495,19 +496,8 @@ struct lua_Debug {
 /* }====================================================================== */
 
 
-#define LUAI_TOSTRAUX(x)	#x
-#define LUAI_TOSTR(x)		LUAI_TOSTRAUX(x)
-
-#define LUA_VERSION_MAJOR	LUAI_TOSTR(LUA_VERSION_MAJOR_N)
-#define LUA_VERSION_MINOR	LUAI_TOSTR(LUA_VERSION_MINOR_N)
-#define LUA_VERSION_RELEASE	LUAI_TOSTR(LUA_VERSION_RELEASE_N)
-
-#define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
-#define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
-
-
 /******************************************************************************
-* Copyright (C) 1994-2023 Lua.org, PUC-Rio.
+* Copyright (C) 1994-2024 Lua.org, PUC-Rio.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the

luaconf.h

@@ -261,7 +261,7 @@
 /*
 ** LUA_IGMARK is a mark to ignore all after it when building the
 ** module name (e.g., used to build the luaopen_ function name).
-** Typically, the sufix after the mark is the module version,
+** Typically, the suffix after the mark is the module version,
 ** as in "mod-v1.2.so".
 */
 #define LUA_IGMARK		"-"

lundump.h

@@ -21,7 +21,7 @@
 /*
 ** Encode major-minor version in one byte, one nibble for each
 */
-#define LUAC_VERSION	(LUA_VERSION_MAJOR_N*16+LUA_VERSION_MINOR_N)
+#define LUAC_VERSION  (((LUA_VERSION_NUM / 100) * 16) + LUA_VERSION_NUM % 100)
 
 #define LUAC_FORMAT	0	/* this is the official format */
 

lvm.c

@@ -92,7 +92,7 @@ static int l_strton (const TValue *obj, TValue *result) {
   if (!cvt2num(obj))  /* is object not a string? */
     return 0;
   else {
-  TString *st = tsvalue(obj);
+    TString *st = tsvalue(obj);
     return (luaO_str2num(getstr(st), result) == tsslen(st) + 1);
   }
 }

manual/2html

@@ -30,7 +30,7 @@ by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes
 <p>
 <small>
 <a href="http://www.lua.org/copyright.html">Copyright</a>
-&copy; 2023 Lua.org, PUC-Rio.  All rights reserved.
+&copy; 2024 Lua.org, PUC-Rio.  All rights reserved.
 </small>
 <hr>
 

manual/manual.of

@@ -289,7 +289,7 @@ Whenever there is an error,
 an @def{error object}
 is propagated with information about the error.
 Lua itself only generates errors whose error object is a string,
-but programs may generate errors with
+but programs can generate errors with
 any value as the error object.
 It is up to the Lua program or its host to handle such error objects.
 For historical reasons,
@@ -298,7 +298,7 @@ even though it does not have to be a string.
 
 
 When you use @Lid{xpcall} (or @Lid{lua_pcall}, in C)
-you may give a @def{message handler}
+you can give a @def{message handler}
 to be called in case of errors.
 This function is called with the original error object
 and returns a new error object.
@@ -343,7 +343,7 @@ which is then called a @def{metamethod}.
 In the previous example, the key is the string @St{__add}
 and the metamethod is the function that performs the addition.
 Unless stated otherwise,
-a metamethod may in fact be any @x{callable value},
+a metamethod can in fact be any @x{callable value},
 which is either a function or a value with a @idx{__call} metamethod.
 
 You can query the metatable of any value
@@ -1417,7 +1417,7 @@ labels in Lua are considered statements too:
 
 A label is visible in the entire block where it is defined,
 except inside nested functions.
-A goto may jump to any visible label as long as it does not
+A goto can jump to any visible label as long as it does not
 enter into the scope of a local variable.
 A label should not be declared
 where a label with the same name is visible,
@@ -4416,7 +4416,7 @@ otherwise, returns @id{NULL}.
 }
 
 @APIEntry{void lua_toclose (lua_State *L, int index);|
-@apii{0,0,m}
+@apii{0,0,v}
 
 Marks the given index in the stack as a
 to-be-closed slot @see{to-be-closed}.
@@ -4433,6 +4433,9 @@ A slot marked as to-be-closed should not be removed from the stack
 by any other function in the API except @Lid{lua_settop} or @Lid{lua_pop},
 unless previously deactivated by @Lid{lua_closeslot}.
 
+This function raises an error if the value at the given slot
+neither has a @idx{__close} metamethod nor is a false value.
+
 This function should not be called for an index
 that is equal to or below an active to-be-closed slot.
 
@@ -4488,7 +4491,7 @@ but can contain other zeros in its body.
 
 This function can raise memory errors only
 when converting a number to a string
-(as then it has to create a new string).
+(as then it may create a new string).
 
 }
 
@@ -8773,13 +8776,13 @@ The returned table can contain all the fields returned by @Lid{lua_getinfo},
 with the string @id{what} describing which fields to fill in.
 The default for @id{what} is to get all information available,
 except the table of valid lines.
-If present,
-the option @Char{f}
+The option @Char{f}
 adds a field named @id{func} with the function itself.
-If present,
-the option @Char{L}
-adds a field named @id{activelines} with the table of
-valid lines.
+The option @Char{L} adds a field named @id{activelines}
+with the table of valid lines,
+provided the function is a Lua function.
+If the function has no debug information,
+the table is empty.
 
 For instance, the expression @T{debug.getinfo(1,"n").name} returns
 a name for the current function,

testes/db.lua

@@ -49,6 +49,15 @@ do
 end
 
 
+--  bug in 5.4.4-5.4.6: activelines in vararg functions
+--  without debug information
+do
+  local func = load(string.dump(load("print(10)"), true))
+  local actl = debug.getinfo(func, "L").activelines
+  assert(#actl == 0)   -- no line info
+end
+
+
 -- test file and string names truncation
 local a = "function f () end"
 local function dostring (s, x) return load(s, x)() end

testes/errors.lua

@@ -91,7 +91,7 @@ end
 
 if not T then
   (Message or print)
-    ('\n >>> testC not active: skipping memory message test <<<\n')
+    ('\n >>> testC not active: skipping tests for messages in C <<<\n')
 else
   print "testing memory error message"
   local a = {}
@@ -104,6 +104,19 @@ else
   end)
   T.totalmem(0)
   assert(not st and msg == "not enough" .. " memory")
+
+  -- stack space for luaL_traceback (bug in 5.4.6)
+  local res = T.testC[[
+    # push 16 elements on the stack
+    pushnum 1; pushnum 1; pushnum 1; pushnum 1; pushnum 1;
+    pushnum 1; pushnum 1; pushnum 1; pushnum 1; pushnum 1;
+    pushnum 1; pushnum 1; pushnum 1; pushnum 1; pushnum 1;
+    pushnum 1;
+    # traceback should work with 4 remaining slots
+    traceback xuxu 1;
+    return 1
+  ]]
+  assert(string.find(res, "xuxu.-main chunk"))
 end
 
 

testes/pm.lua

@@ -56,7 +56,8 @@ assert(f("  \n\r*&\n\r   xuxu  \n\n", "%g%g%g+") == "xuxu")
 
 -- Adapt a pattern to UTF-8
 local function PU (p)
-  -- break '?' into each individual byte of a character
+  -- reapply '?' into each individual byte of a character.
+  -- (For instance, "á?" becomes "\195?\161?".)
   p = string.gsub(p, "(" .. utf8.charpattern .. ")%?", function (c)
     return string.gsub(c, ".", "%0?")
   end)