Improve locus tracker; provide a testsuite

* include/mailutils/locus.h (mu_locus_track_stat): New struct.
(mu_locus_tracker_stat): New proto.
(mu_locus_tracker_retreat): Change return type.
* libmailutils/locus/debug.c (mu_stream_vlprintf): Don't print
spurious \n.
(mu_lrange_debug): Fix incorrect call.
* libmailutils/locus/tracker.c (mu_locus_track_create): Allocate storage
for at least two lines of text.
(mu_locus_tracker_stat): New function.
(mu_locus_tracker_advance): Handle empty lines
(mu_locus_tracker_retreat): Add error handling.
* libmailutils/tests/Makefile.am (noinst_PROGRAMS): Add locktrack.
* libmailutils/tests/tracker.c: Rename to loctrack.c
* libmailutils/tests/testsuite.at: Add new testcase.
* libmailutils/tests/loctrack.at: New test case.

@@ -19,6 +19,13 @@ struct mu_locus_range
 
 typedef struct mu_locus_track *mu_locus_track_t;
 
+struct mu_locus_track_stat
+{
+  unsigned start_line;
+  size_t n_lines;
+  size_t n_chars;
+};
+  
 int mu_ident_ref (char const *name, char const **refname);
 int mu_ident_deref (char const *);
 
@@ -48,7 +55,10 @@ size_t mu_locus_track_level (mu_locus_track_t trk);
 void mu_locus_tracker_advance (struct mu_locus_track *trk,
 			       struct mu_locus_range *loc,
 			       char const *text, size_t leng);
-void mu_locus_tracker_retreat (struct mu_locus_track *trk, size_t n);
+int mu_locus_tracker_retreat (struct mu_locus_track *trk, size_t n);
+int mu_locus_tracker_stat (struct mu_locus_track *trk,
+			   struct mu_locus_track_stat *st);
+
 
 void mu_stream_print_locus_range (mu_stream_t stream,
 				  struct mu_locus_range const *loc);

@@ -59,8 +59,7 @@ mu_stream_vlprintf (mu_stream_t stream,
 {
   mu_stream_print_locus_range (stream, loc);
   mu_stream_write (stream, ": ", 2, NULL);
-  mu_stream_vprintf (mu_strerr, fmt, ap);
-  mu_stream_write (stream, "\n", 1, NULL);
+  mu_stream_vprintf (stream, fmt, ap);
 }
 
 void
@@ -91,8 +90,9 @@ mu_lrange_debug (struct mu_locus_range const *loc,
     }
 
   va_start (ap, fmt);
-  mu_stream_lprintf (mu_strerr, loc, fmt, ap);
+  mu_stream_vlprintf (mu_strerr, loc, fmt, ap);
   va_end (ap);
+  mu_stream_write (mu_strerr, "\n", 1, NULL);
 
   if (rc == 0)
     mu_stream_ioctl (mu_strerr, MU_IOCTL_LOGSTREAM,

@@ -2,6 +2,7 @@
 #include <errno.h>
 #include <mailutils/types.h>
 #include <mailutils/locus.h>
+#include <mailutils/error.h>
 
 struct mu_locus_track
 {
@@ -38,6 +39,8 @@ mu_locus_track_create (mu_locus_track_t *ret,
       return rc;
     }
 
+  if (max_lines < 2)
+    max_lines = 2;
   trk->max_lines = max_lines;
   trk->head = 0;
   trk->level = 0;
@@ -106,14 +109,34 @@ static inline unsigned *
 pop (mu_locus_track_t trk)
 {
   if (trk->level == 0)
-    {
-      *cols_tos_ptr (trk) = 0;
-      return NULL; //FIXME
-    }
+    return NULL;
   trk->level--;
   return cols_tos_ptr (trk);
 }
 
+#ifndef SIZE_MAX
+# define SIZE_MAX (~((size_t)0))
+#endif
+
+int
+mu_locus_tracker_stat (struct mu_locus_track *trk,
+		       struct mu_locus_track_stat *st)
+{
+  size_t i, nch = 0;
+
+  for (i = 0; i <= trk->level; i++)
+    {
+      unsigned n = cols_peek (trk, i);
+      if (SIZE_MAX - nch < n)
+	return ERANGE;
+      nch += n;
+    }
+  
+  st->start_line = trk->hline;
+  st->n_lines = trk->level;
+  st->n_chars = nch;
+}
+    
 void
 mu_locus_tracker_advance (struct mu_locus_track *trk,
 			  struct mu_locus_range *loc,
@@ -142,27 +165,44 @@ mu_locus_tracker_advance (struct mu_locus_track *trk,
     }
   else
     {
+      /* Text ends with a newline.  Keep the previos line number. */
       loc->end.mu_line = trk->hline + trk->level - 1;
       loc->end.mu_col = cols_peek (trk, trk->level - 1) - 1;
-    }
+      if (loc->end.mu_col + 1 == loc->beg.mu_col)
+	{
+	  /* This happens if the previous line contained only newline. */
+	  loc->beg.mu_col = loc->end.mu_col;
+	}	  
+   }
 }
 
-void
+int
 mu_locus_tracker_retreat (struct mu_locus_track *trk, size_t n)
 {
-  unsigned *ptr;
+  struct mu_locus_track_stat st;
 
-  ptr = cols_tos_ptr (trk);
-  while (n--)
+  mu_locus_tracker_stat (trk, &st);
+  if (n > st.n_chars)
+    return ERANGE;
+  else
     {
-      if (*ptr == 0)
+      unsigned *ptr = cols_tos_ptr (trk);
+      while (n--)
 	{
-	  ptr = pop (trk);
-	  if (!ptr)
-	    break;
+	  if (*ptr == 0)
+	    {
+	      ptr = pop (trk);
+	      if (!ptr || *ptr == 0)
+		{
+		  mu_error ("%s:%d: INTERNAL ERROR: out of pop back\n",
+			    __FILE__, __LINE__);
+		  return ERANGE;
+		}
+	    }
+	  --*ptr;
 	}
-      --*ptr;
     }
+  return 0;
 }
     
   

@@ -19,6 +19,7 @@ fsfolder
 globtest
 imapio
 listop
+loctrack
 logstr
 mailcap
 mimehdr
@@ -34,7 +35,6 @@ strout
 strtoc
 tcli
 tempfile
-tracker
 url-comp
 url-parse
 vexp

@@ -54,6 +54,7 @@ noinst_PROGRAMS = \
  globtest\
  imapio\
  listop\
+ loctrack\
  logstr\
  mailcap\
  mimehdr\
@@ -68,7 +69,6 @@ noinst_PROGRAMS = \
  strout\
  strtoc\
  tempfile\
- tracker\
  tcli\
  url-comp\
  url-parse\
@@ -107,6 +107,7 @@ TESTSUITE_AT = \
  inline-comment.at\
  linecon.at\
  list.at\
+ loctrack.at\
  logstr.at\
  mailcap.at\
  mimehdr.at\

+# This file is part of GNU Mailutils. -*- Autotest -*-
+# Copyright (C) 2017 Free Software Foundation, Inc.
+#
+# GNU Mailutils is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 3, or (at
+# your option) any later version.
+#
+# GNU Mailutils is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_BANNER([Locus tracker])
+
+m4_pushdef([TRACKTEST],[
+AT_SETUP([$1])
+AT_KEYWORDS([tracker $2])
+AT_CHECK([loctrack liber $3 <<EOT
+$4[]EOT
+],
+[0],
+[$5],
+[$6])
+AT_CLEANUP
+])
+
+TRACKTEST([normal operation],[],[7],
+[
+agnosco
+veteris\n
+vestigia
+flamme
+\n
+\n
+Publius
+Ovidius
+Naso
+],
+[liber:1.1-7: agnosco
+liber:1.8-14: veteris\n
+liber:2.1-8: vestigia
+liber:2.9-14: flamme
+liber:2.14: \n
+liber:3: \n
+liber:4.1-7: Publius
+liber:4.8-14: Ovidius
+liber:4.15-18: Naso
+])
+
+TRACKTEST([retreat],[],[3],
+[
+agnosco
+\-4
+veteris
+vestigia\n
+flamme
+\-8
+Publius
+],
+[liber:1.1-7: agnosco
+liber:1.4-10: veteris
+liber:1.11-18: vestigia\n
+liber:2.1-6: flamme
+liber:1.18-24: Publius
+])
+
+TRACKTEST([retreat over several lines],[],[4],
+[
+one\n
+two\n
+three
+\-11
+four
+],
+[liber:1.1-3: one\n
+liber:2.1-3: two\n
+liber:3.1-5: three
+liber:1.3-6: four
+])
+
+TRACKTEST([retreat to the beginning],[],[4],
+[one\n
+two\n
+\-8
+three
+],
+[liber:1.1-3: one\n
+liber:2.1-3: two\n
+liber:1.1-5: three
+])
+
+TRACKTEST([too big retreat],[],[2],
+[one\n
+two\n
+\-10
+three
+],
+[liber:1.1-3: one\n
+liber:2.1-3: two\n
+liber:3.1-5: three
+],
+[loctrack: retreat count too big
+])
+
+m4_popdef([TRACKTEST])
\ No newline at end of file

@@ -33,22 +33,29 @@ main (int argc, char **argv)
       char *tok;
       
       n = mu_rtrim_class (buf, MU_CTYPE_SPACE);
-      if (buf[0] == '\\')
+      if (n == 0)
+	continue;
+      if (buf[0] == '\\' && buf[1] == '-')
 	{
-	  long x = strtol (buf+1, &end, 10);
+	  long x = strtol (buf+2, &end, 10);
 	  if (*end || x == 0)
 	    {
 	      mu_error ("bad number");
 	      continue;
 	    }
-	  mu_locus_tracker_retreat (trk, x);
+	  rc = mu_locus_tracker_retreat (trk, x);
+	  if (rc == ERANGE)
+	    mu_error ("retreat count too big");
+	  else if (rc)
+	    mu_diag_funcall (MU_DIAG_ERROR, "mu_locus_tracker_retreat", buf+2,
+			     rc);
 	}
       else
 	{
 	  mu_c_str_unescape (buf, "\\\n", "\\n", &tok);
 	  mu_locus_tracker_advance (trk, &lr, tok, strlen (tok));
 	  free (tok);
-	  mu_lrange_debug (&lr, "%s", buf);
+	  mu_stream_lprintf (mu_strout, &lr, "%s\n", buf);
 	}
     }
   return 0;

@@ -212,3 +212,4 @@ m4_include([msgset.at])
 
 m4_include([globtest.at])
 
+m4_include([loctrack.at])