Change algorithm to find lesskey and history files:

Previously, less would look for lesskey in $HOME/.lesskey.
Now it looks in $XDG_CONFIG_DIR/lesskey first, and if not found then $HOME/.lesskey.

Previously, less would look for history in $HOME/.lesshst.
Now it looks in $XDG_CONFIG_DIR/lesshst first, and if not found then $HOME/.lesshst.

When writing the history file, it uses $XDG_CONFIG_DIR/lesshst if it exists,
otherwise $HOME/.lesshst if it exists, otherwise $XDG_CONFIG_DIR/lesshst.

cmdbuf.c

@@ -1394,11 +1394,12 @@ mlist_size(ml)
  * Get the name of the history file.
  */
  static char *
-histfile_name(VOID_PARAM)
+histfile_name(must_exist)
+ int must_exist;
 {
  char *home;
+ char *xdg;
  char *name;
- int len;
 
  /* See if filename is explicitly specified by $LESSHISTFILE. */
  name = lgetenv("LESSHISTFILE");
@@ -1414,19 +1415,25 @@ histfile_name(VOID_PARAM)
  if (strcmp(LESSHISTFILE, "") == 0 || strcmp(LESSHISTFILE, "-") == 0)
  return (NULL);
 
- /* Otherwise, file is in $HOME. */
+ /* Try in $XDG_DATA_HOME first, then in $HOME. */
+ xdg = lgetenv("XDG_DATA_HOME");
  home = lgetenv("HOME");
- if (isnullenv(home))
- {
 #if OS2
+ if (isnullenv(home))
  home = lgetenv("INIT");
- if (isnullenv(home))
 #endif
- return (NULL);
+ name = NULL;
+ if (!must_exist)
+ {
+ /* If we're writing the file and the file already exists, use it. */
+ name = dirfile(xdg, LESSHISTFILE+1, 1);
+ if (name == NULL)
+ name = dirfile(home, LESSHISTFILE, 1);
  }
- len = (int) (strlen(home) + strlen(LESSHISTFILE) + 2);
- name = (char *) ecalloc(len, sizeof(char));
- SNPRINTF2(name, len, "%s/%s", home, LESSHISTFILE);
+ if (name == NULL)
+ name = dirfile(xdg, LESSHISTFILE+1, must_exist);
+ if (name == NULL)
+ name = dirfile(home, LESSHISTFILE, must_exist);
  return (name);
 }
 
@@ -1447,7 +1454,7 @@ read_cmdhist2(action, uparam, skip_search, skip_shell)
  char *p;
  int *skip = NULL;
 
- filename = histfile_name();
+ filename = histfile_name(1);
  if (filename == NULL)
  return;
  f = fopen(filename, "r");
@@ -1693,7 +1700,7 @@ save_cmdhist(VOID_PARAM)
 
  if (!histfile_modified())
  return;
- histname = histfile_name();
+ histname = histfile_name(0);
  if (histname == NULL)
  return;
  tempname = make_tempname(histname);

decode.c

@@ -932,10 +932,16 @@ add_hometable(call_lesskey, envname, def_filename, sysvar)
 
  if (envname != NULL && (filename = lgetenv(envname)) != NULL)
  filename = save(filename);
- else if (sysvar)
+ else if (sysvar) /* def_filename is full path */
  filename = save(def_filename);
- else
- filename = homefile(def_filename);
+ else /* def_filename is just basename */
+ {
+ char *xdg = lgetenv("XDG_CONFIG_HOME");
+ if (!isnullenv(xdg))
+ filename = dirfile(xdg, def_filename+1, 1);
+ if (filename == NULL)
+ filename = homefile(def_filename);
+ }
  if (filename == NULL)
  return -1;
  r = (*call_lesskey)(filename, sysvar);

filename.c

@@ -209,10 +209,11 @@ shell_quote(s)
  * Return a pathname that points to a specified file in a specified directory.
  * Return NULL if the file does not exist in the directory.
  */
- static char *
-dirfile(dirname, filename)
+ public char *
+dirfile(dirname, filename, must_exist)
  char *dirname;
  char *filename;
+ int must_exist;
 {
  char *pathname;
  int len;
@@ -228,17 +229,20 @@ dirfile(dirname, filename)
  if (pathname == NULL)
  return (NULL);
  SNPRINTF3(pathname, len, "%s%s%s", dirname, PATHNAME_SEP, filename);
- /*
- * Make sure the file exists.
- */
- f = open(pathname, OPEN_READ);
- if (f < 0)
- {
- free(pathname);
- pathname = NULL;
- } else
+ if (must_exist)
  {
- close(f);
+ /*
+ * Make sure the file exists.
+ */
+ f = open(pathname, OPEN_READ);
+ if (f < 0)
+ {
+ free(pathname);
+ pathname = NULL;
+ } else
+ {
+ close(f);
+ }
  }
  return (pathname);
 }
@@ -252,24 +256,18 @@ homefile(filename)
 {
  char *pathname;
 
- /*
- * Try $HOME/filename.
- */
- pathname = dirfile(lgetenv("HOME"), filename);
+ /* Try $HOME/filename. */
+ pathname = dirfile(lgetenv("HOME"), filename, 1);
  if (pathname != NULL)
  return (pathname);
 #if OS2
- /*
- * Try $INIT/filename.
- */
- pathname = dirfile(lgetenv("INIT"), filename);
+ /* Try $INIT/filename. */
+ pathname = dirfile(lgetenv("INIT"), filename, 1);
  if (pathname != NULL)
  return (pathname);
 #endif
 #if MSDOS_COMPILER || OS2
- /*
- * Look for the file anywhere on search path.
- */
+ /* Look for the file anywhere on search path. */
  pathname = (char *) ecalloc(_MAX_PATH, sizeof(char));
 #if MSDOS_COMPILER==DJGPPC
  {
@@ -1118,4 +1116,3 @@ last_component(name)
  }
  return (name);
 }
-

less.nro.VER

@@ -1260,7 +1260,7 @@ Otherwise,
 looks in a standard place for the lesskey source file:
 On Unix systems,
 .I less
-looks for a lesskey file called "$HOME/.lesskey".
+looks for a lesskey file called "$XDG_CONFIG_HOME/lesskey" or "$HOME/.lesskey".
 On MS-DOS and Windows systems,
 .I less
 looks for a lesskey file called "$HOME/_lesskey", and if it is not found there,
@@ -1919,8 +1919,9 @@ Name of the history file used to remember search commands and
 shell commands between invocations of
 .IR less .
 If set to "\-" or "/dev/null", a history file is not used.
-The default is "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on
-DOS and Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
+The default is "$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst" on Unix systems,
+"$HOME/_lesshst" on DOS and Windows systems,
+or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
 on OS/2 systems.
 .IP LESSHISTSIZE
 The maximum number of commands to save in the history file.

lesskey.nro.VER

@@ -27,7 +27,8 @@ source file into a format understood by
 This compilation step is no longer required and the
 .I lesskey
 program is therefore deprecated although the file format remains supported by
-.IR less .
+.I less
+itself.
 .PP
 .SH FILE FORMAT
 The input file consists of one or more