test: piece-table-internals: Add test and pass it

Fixes the optimization that avoids adding a new piece when the addition
happens in the end of the buffer.

Fixes leaks produced in piece_table_optimize

3 files changed, 76 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index 7123907..95f3c1e 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,8 @@ HEADERS = $(wildcard src/*.h)
 
 TEST := 					\
 	piece-table-delete		\
-	piece-table-insert
+	piece-table-insert		\
+	piece-table-internals
 TEST_FILES = $(addprefix tests/, $(TEST))
 TEST_SOURCES = $(addsuffix .c, $(addprefix tests/, $(TEST)))
 
diff --git a/src/piece-table.c b/src/piece-table.c
index 36556ae..40d8407 100644
--- a/src/piece-table.c
+++ b/src/piece-table.c
@@ -119,7 +119,8 @@ void
 piece_buffer_empty (piece_buffer *pb)
 {
   piece_buffer_destroy (pb->next);
-  pb->start -= pb->used;
+  pb->next = NULL;
+  pb->used = 0;
 }
 
 piece *
@@ -270,7 +271,7 @@ piece_table_insert (piece_table *pt, size_t pos, char *in, size_t len)
   if ( pt->add.used != 0 &&
        start->buffer == &pt->add &&
        pt->cached_offset + start->length == pos &&
-       pt->add.used == start->start + start->length ) {
+       pt->add.used == start->start + start->length + len ) {
       pt->length += len;
       start->length += len;
       return;
@@ -421,12 +422,11 @@ piece_table_optimize (piece_table *pt)
   piece *p;
   char *buff = malloc (sizeof (*buff) * pt->length + 1); /*TODO remove +1*/
   piece_table_to_string (pt, buff, pt->length);
-
   text_buffer_fill (&pt->orig, buff, pt->length);
+  free (buff);
+  text_buffer_empty (&pt->add);
   text_buffer_init (&pt->add);
 
-  for (p = pt->sentinel->next; p != pt->sentinel; p = p->next)
-    piece_table_piece_mark_empty (pt, p);
   piece_buffer_empty (pt->pieces);
 
   pt->sentinel = piece_buffer_bump (pt->pieces);
@@ -441,4 +441,7 @@ piece_table_optimize (piece_table *pt)
   p->start = 0;
   p->length = pt->length;
   p->buffer = &pt->orig;
+
+  pt->cached_offset = 0;
+  pt->cached = p;
 }
diff --git a/tests/piece-table-internals.c b/tests/piece-table-internals.c
new file mode 100644
index 0000000..d59da17
--- /dev/null
+++ b/tests/piece-table-internals.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "../src/piece-table-internals.h"
+
+size_t
+count_pieces (piece_table *pt)
+{
+  size_t count;
+  piece *p;
+  for (count = 0, p = pt->sentinel->next; p != pt->sentinel; p = p->next)
+    count++;
+  return count;
+}
+
+int
+main ()
+{
+  char tmp[100];
+  size_t expected_count;
+  piece_table *pt = piece_table_create_from ("0123456789", 10);
+  /** Inserting **/
+  /* Should add pieces... */
+  expected_count = 1;
+  if (count_pieces (pt) != expected_count) return 10;
+
+  piece_table_insert (pt, 10, "abcdefgh", 8);
+  expected_count++;
+  if (count_pieces (pt) != expected_count) return 11;
+
+  /* ... but not always **/
+  piece_table_insert (pt, 18, "abcdefgh", 8);
+  if (count_pieces (pt) != expected_count) return 12;
+
+
+  /** Deleting **/
+  piece_table_delete (pt, 23, 3);
+  if (count_pieces (pt) != expected_count) return 20;
+
+  piece_table_delete (pt, 13, 4);
+  expected_count++;
+  if (count_pieces (pt) != expected_count) return 21;
+
+  piece_table_delete (pt, 0, 10);
+  expected_count--;
+  if (count_pieces (pt) != expected_count) return 22;
+
+
+  /** Result **/
+  piece_table_to_string (pt, tmp, 99);
+  if (strcmp (tmp, "abchabcde"))
+    return 30;
+
+  /** Optimize **/
+  piece_table_optimize (pt);
+  expected_count = 1;
+  if (count_pieces (pt) != expected_count) return 40;
+
+  /** Result **/
+  piece_table_to_string (pt, tmp, 99);
+  if (strcmp (tmp, "abchabcde"))
+    return 50;
+
+  piece_table_destroy (pt);
+  return 0;
+}