Option '-l' discards version sufix from file name

Like 'require', the command-line option '-l' discards an optional
version suffix (everything after an hyphen) from a file name when
creating the module name.

loadlib.c

@@ -24,15 +24,6 @@
 #include "lualib.h"
 
 
-/*
-** LUA_IGMARK is a mark to ignore all before it when building the
-** luaopen_ function name.
-*/
-#if !defined (LUA_IGMARK)
-#define LUA_IGMARK		"-"
-#endif
-
-
 /*
 ** LUA_CSUBSEP is the character that replaces dots in submodule names
 ** when searching for a C loader.

lua.c

@@ -210,12 +210,17 @@ 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.
 */
 static int dolibrary (lua_State *L, char *globname) {
   int status;
+  char *suffix = NULL;
   char *modname = strchr(globname, '=');
-  if (modname == NULL)  /* no explicit name? */
+  if (modname == NULL) {  /* no explicit name? */
     modname = globname;  /* module name is equal to global name */
+    suffix = strchr(modname, *LUA_IGMARK);  /* look for a suffix mark */
+  }
   else {
     *modname = '\0';  /* global name ends here */
     modname++;  /* module name starts after the '=' */
@@ -223,8 +228,11 @@ static int dolibrary (lua_State *L, char *globname) {
   lua_getglobal(L, "require");
   lua_pushstring(L, modname);
   status = docall(L, 1, 1);  /* call 'require(modname)' */
-  if (status == LUA_OK)
+  if (status == LUA_OK) {
+    if (suffix != NULL)  /* is there a suffix mark? */
+      *suffix = '\0';  /* remove sufix from global name */
     lua_setglobal(L, globname);  /* globname = require(modname) */
+  }
   return report(L, status);
 }
 

luaconf.h

@@ -257,6 +257,15 @@
 
 #endif
 
+
+/*
+** 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,
+** as in "mod-v1.2.so".
+*/
+#define LUA_IGMARK		"-"
+
 /* }================================================================== */
 
 

testes/main.lua

@@ -225,6 +225,13 @@ prepfile("print(str.upper'alo alo', m.max(10, 20))")
 RUN("lua -l 'str=string' '-lm=math' -e 'print(m.sin(0))' %s > %s", prog, out)
 checkout("0.0\nALO ALO\t20\n")
 
+
+-- test module names with version sufix ("libs/lib2-v2")
+RUN("env LUA_CPATH='./libs/?.so' lua -l lib2-v2 -e 'print(lib2.id())' > %s",
+    out)
+checkout("true\n")
+
+
 -- test 'arg' table
 local a = [[
   assert(#arg == 3 and arg[1] == 'a' and