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author | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2020-10-26 11:15:51 -0300 |
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committer | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2020-10-26 11:15:51 -0300 |
commit | 69b71a69197de0cb6f7f58f5d7c55d9a9a6e529d (patch) | |
tree | 8323373db70b7feb06691634c5431c3d6bbe9f3e /lua.c | |
parent | d742a193e57029d973aff0a5eb04d8ddd03fa0ff (diff) | |
download | lua-github-69b71a69197de0cb6f7f58f5d7c55d9a9a6e529d.tar.gz |
_PROMPT can have non-string values
'get_prompt' uses 'luaL_tolstring' to convert _PROMPT or _PROMPT2
value to a string. That conversion may invoke a '__tostring'
metamethod.
Diffstat (limited to 'lua.c')
-rw-r--r-- | lua.c | 16 |
1 files changed, 10 insertions, 6 deletions
@@ -416,14 +416,18 @@ static int handle_luainit (lua_State *L) { /* -** Returns the string to be used as a prompt by the interpreter. +** Return the string to be used as a prompt by the interpreter. Leave +** the string (or nil, if using the default value) on the stack, to keep +** it anchored. */ static const char *get_prompt (lua_State *L, int firstline) { - const char *p; - lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2"); - p = lua_tostring(L, -1); - if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2); - return p; + if (lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2") == LUA_TNIL) + return (firstline ? LUA_PROMPT : LUA_PROMPT2); /* use the default */ + else { /* apply 'tostring' over the value */ + const char *p = luaL_tolstring(L, -1, NULL); + lua_remove(L, -2); /* remove original value */ + return p; + } } /* mark in error messages for incomplete statements */ |