wordsplit: rewrite positional parameters implementation

This improves 3e07e3ad

* include/wordsplit.h (ws_paramv,ws_paramc)
(ws_parambuf,ws_paramidx,ws_paramsiz): New fields.
(WRDSO_PARAMV,WRDSO_PARAM_NEGIDX): New options.
(WRDSE_BADPARAM): New error code.
(wordsplit_free_parambuf): New proto.
* src/wordsplit.c (wordsplit_init): Initialize new fields.
(wsplt_assign_var): Fix double-free and memory leak.
(expvar): Expand positional parameters.
(begin_var_p): Add '#'
(wordsplit_free_envbuf): Fix condition.
(wordsplit_free_parambuf): New function.
(wordsplit_free): Call wordsplit_free_parambuf.
(_wordsplit_errstr): New error description.
* tests/wordsplit.at: Update wsp invocations.
Test positional parameters.
* tests/wsp.c: Rewrite.

1 files changed, 18 insertions, 0 deletions

diff --git a/include/wordsplit.h b/include/wordsplit.h
index a175275..d7eb26f 100644
--- a/include/wordsplit.h
+++ b/include/wordsplit.h
@@ -73,12 +73,22 @@ struct wordsplit
 	   to ws_env. From this moment on, all variable expansions are served
 	   from ws_envbuf. */
   char **ws_envbuf;         /* Storage for variables */
   size_t ws_envidx;         /* Index of first free slot */
   size_t ws_envsiz;         /* Size of the ws_envbuf array */
 
+  char const **ws_paramv;   /* [WRDSO_PARAMV] User-supplied positional
+			       parameters */
+  size_t ws_paramc;         /* Number of positional parameters */
+
+        /* Temporary storage for parameters. Works similarly to ws_enbuf.
+	 */
+  char **ws_parambuf;
+  size_t ws_paramidx;
+  size_t ws_paramsiz;
+  
   int (*ws_getvar) (char **ret, const char *var, size_t len, void *clos);
                             /* [Input] (WRDSF_GETVAR, !WRDSF_NOVAR) Looks up
 			       the name VAR (LEN bytes long) in the table of
 			       variables and if found returns in memory
 			       location pointed to by RET the value of that
 			       variable.  Returns WRDSE_OK (0) on success,
@@ -223,12 +233,18 @@ struct wordsplit
    (e.g. ${VAR:-foo bar}) */
 #define WRDSO_NOVARSPLIT     0x00001000
 /* Don't split commands, even containing whitespace, e.g.
    $(echo foo bar) */
 #define WRDSO_NOCMDSPLIT     0x00002000
 
+/* Enable positional parameters */
+#define WRDSO_PARAMV         0x00004000
+/* Enable negative positional indices (${-1} is the last positional
+   parameter) */
+#define WRDSO_PARAM_NEGIDX   0x00008000
+
 #define WRDSO_BSKEEP          WRDSO_BSKEEP_WORD     
 #define WRDSO_OESC            WRDSO_OESC_WORD       
 #define WRDSO_XESC            WRDSO_XESC_WORD       
 
 /* Indices into ws_escape */
 #define WRDSX_WORD  0
@@ -247,18 +263,20 @@ struct wordsplit
 #define WRDSE_CBRACE     4
 #define WRDSE_UNDEF      5
 #define WRDSE_NOINPUT    6
 #define WRDSE_PAREN      7
 #define WRDSE_GLOBERR    8
 #define WRDSE_USERERR    9
+#define WRDSE_BADPARAM  10
 
 int wordsplit (const char *s, wordsplit_t *ws, int flags);
 int wordsplit_len (const char *s, size_t len, wordsplit_t *ws, int flags);
 void wordsplit_free (wordsplit_t *ws);
 void wordsplit_free_words (wordsplit_t *ws);
 void wordsplit_free_envbuf (wordsplit_t *ws);
+void wordsplit_free_parambuf (struct wordsplit *ws);
 int wordsplit_get_words (wordsplit_t *ws, size_t *wordc, char ***wordv);
 
 static inline void wordsplit_getwords (wordsplit_t *ws, size_t *wordc, char ***wordv)
   __attribute__ ((deprecated));
 
 static inline void