Add many calls to CHECK_TOTAL_LENGTH.

(set_intervals_multibyte_1): When becoming
multibyte, adjust right and left child sizes to a whole set of
characters.  If an interval gets zero total-length, delete it.
If an interval consists of just its children, delete one of them.

1 files changed, 88 insertions, 0 deletions

diff --git a/src/intervals.c b/src/intervals.c
index 3b8327b96d8..c393628dc4f 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -75,12 +75,14 @@ create_root_interval (parent)
     {
       new->total_length = (BUF_Z (XBUFFER (parent))
                            - BUF_BEG (XBUFFER (parent)));
+      CHECK_TOTAL_LENGTH (new);
       BUF_INTERVALS (XBUFFER (parent)) = new;
       new->position = 1;
     }
   else if (STRINGP (parent))
     {
       new->total_length = SCHARS (parent);
+      CHECK_TOTAL_LENGTH (new);
       STRING_SET_INTERVALS (parent, new);
       new->position = 0;
     }
@@ -338,9 +340,11 @@ rotate_right (interval)
 
   /* A's total length is decreased by the length of B and its left child.  */
   interval->total_length -= B->total_length - LEFT_TOTAL_LENGTH (interval);
+  CHECK_TOTAL_LENGTH (interval);
 
   /* B must have the same total length of A.  */
   B->total_length = old_total;
+  CHECK_TOTAL_LENGTH (B);
 
   return B;
 }
@@ -384,9 +388,11 @@ rotate_left (interval)
 
   /* A's total length is decreased by the length of B and its right child.  */
   interval->total_length -= B->total_length - RIGHT_TOTAL_LENGTH (interval);
+  CHECK_TOTAL_LENGTH (interval);
 
   /* B must have the same total length of A.  */
   B->total_length = old_total;
+  CHECK_TOTAL_LENGTH (B);
 
   return B;
 }
@@ -405,6 +411,7 @@ balance_an_interval (i)
       old_diff = LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i);
       if (old_diff > 0)
         {
+          /* Since the left child is longer, there must be one.  */
           new_diff = i->total_length - i->left->total_length
             + RIGHT_TOTAL_LENGTH (i->left) - LEFT_TOTAL_LENGTH (i->left);
           if (abs (new_diff) >= old_diff)
@@ -414,6 +421,7 @@ balance_an_interval (i)
         }
       else if (old_diff < 0)
         {
+          /* Since the right child is longer, there must be one.  */
           new_diff = i->total_length - i->right->total_length
             + LEFT_TOTAL_LENGTH (i->right) - RIGHT_TOTAL_LENGTH (i->right);
           if (abs (new_diff) >= -old_diff)
@@ -514,6 +522,7 @@ split_interval_right (interval, offset)
     {
       interval->right = new;
       new->total_length = new_length;
+      CHECK_TOTAL_LENGTH (new);
     }
   else
     {
@@ -522,6 +531,7 @@ split_interval_right (interval, offset)
       SET_INTERVAL_PARENT (interval->right, new);
       interval->right = new;
       new->total_length = new_length + new->right->total_length;
+      CHECK_TOTAL_LENGTH (new);
       balance_an_interval (new);
     }
 
@@ -559,6 +569,7 @@ split_interval_left (interval, offset)
     {
       interval->left = new;
       new->total_length = new_length;
+      CHECK_TOTAL_LENGTH (new);
     }
   else
     {
@@ -567,6 +578,7 @@ split_interval_left (interval, offset)
       SET_INTERVAL_PARENT (new->left, new);
       interval->left = new;
       new->total_length = new_length + new->left->total_length;
+      CHECK_TOTAL_LENGTH (new);
       balance_an_interval (new);
     }
 
@@ -828,6 +840,7 @@ adjust_intervals_for_insertion (tree, position, length)
       if (relative_position <= LEFT_TOTAL_LENGTH (this))
         {
           this->total_length += length;
+          CHECK_TOTAL_LENGTH (this);
           this = this->left;
         }
       else if (relative_position > (TOTAL_LENGTH (this)
@@ -836,6 +849,7 @@ adjust_intervals_for_insertion (tree, position, length)
           relative_position -= (TOTAL_LENGTH (this)
                                 - RIGHT_TOTAL_LENGTH (this));
           this->total_length += length;
+          CHECK_TOTAL_LENGTH (this);
           this = this->right;
         }
       else
@@ -843,6 +857,7 @@ adjust_intervals_for_insertion (tree, position, length)
           /* If we are to use zero-length intervals as buffer pointers,
              then this code will have to change.  */
           this->total_length += length;
+          CHECK_TOTAL_LENGTH (this);
           this->position = LEFT_TOTAL_LENGTH (this)
                            + position - relative_position + 1;
           return tree;
@@ -987,6 +1002,7 @@ adjust_intervals_for_insertion (tree, position, length)
       for (temp = prev ? prev : i; temp; temp = INTERVAL_PARENT_OR_NULL (temp))
         {
           temp->total_length += length;
+          CHECK_TOTAL_LENGTH (temp);
           temp = balance_possible_root_interval (temp);
         }
 
@@ -1043,6 +1059,7 @@ adjust_intervals_for_insertion (tree, position, length)
       for (temp = i; temp; temp = INTERVAL_PARENT_OR_NULL (temp))
         {
           temp->total_length += length;
+          CHECK_TOTAL_LENGTH (temp);
           temp = balance_possible_root_interval (temp);
         }
     }
@@ -1247,6 +1264,7 @@ delete_node (i)
       this = this->left;
       this->total_length += migrate_amt;
     }
+  CHECK_TOTAL_LENGTH (this);
   this->left = migrate;
   SET_INTERVAL_PARENT (migrate, this);
 
@@ -1331,6 +1349,7 @@ interval_deletion_adjustment (tree, from, amount)
                                                    relative_position,
                                                    amount);
       tree->total_length -= subtract;
+      CHECK_TOTAL_LENGTH (tree);
       return subtract;
     }
   /* Right branch */
@@ -1345,6 +1364,7 @@ interval_deletion_adjustment (tree, from, amount)
                                                relative_position,
                                                amount);
       tree->total_length -= subtract;
+      CHECK_TOTAL_LENGTH (tree);
       return subtract;
     }
   /* Here -- this node.  */
@@ -1359,6 +1379,7 @@ interval_deletion_adjustment (tree, from, amount)
         amount = my_amount;
 
       tree->total_length -= amount;
+      CHECK_TOTAL_LENGTH (tree);
       if (LENGTH (tree) == 0)
         delete_interval (tree);
 
@@ -1402,6 +1423,7 @@ adjust_intervals_for_deletion (buffer, start, length)
   if (ONLY_INTERVAL_P (tree))
     {
       tree->total_length -= length;
+      CHECK_TOTAL_LENGTH (tree);
       return;
     }
 
@@ -1457,6 +1479,7 @@ merge_interval_right (i)
 
   /* Zero out this interval.  */
   i->total_length -= absorb;
+  CHECK_TOTAL_LENGTH (i);
 
   /* Find the succeeding interval.  */
   if (! NULL_RIGHT_CHILD (i))      /* It's below us.  Add absorb
@@ -1466,10 +1489,12 @@ merge_interval_right (i)
       while (! NULL_LEFT_CHILD (successor))
         {
           successor->total_length += absorb;
+          CHECK_TOTAL_LENGTH (successor);
           successor = successor->left;
         }
 
       successor->total_length += absorb;
+      CHECK_TOTAL_LENGTH (successor);
       delete_interval (i);
       return successor;
     }
@@ -1487,6 +1512,7 @@ merge_interval_right (i)
 
       successor = INTERVAL_PARENT (successor);
       successor->total_length -= absorb;
+      CHECK_TOTAL_LENGTH (successor);
     }
 
   /* This must be the rightmost or last interval and cannot
@@ -1510,6 +1536,7 @@ merge_interval_left (i)
 
   /* Zero out this interval.  */
   i->total_length -= absorb;
+  CHECK_TOTAL_LENGTH (i);
 
   /* Find the preceding interval.  */
   if (! NULL_LEFT_CHILD (i))    /* It's below us. Go down,
@@ -1519,10 +1546,12 @@ merge_interval_left (i)
       while (! NULL_RIGHT_CHILD (predecessor))
         {
           predecessor->total_length += absorb;
+          CHECK_TOTAL_LENGTH (predecessor);
           predecessor = predecessor->right;
         }
 
       predecessor->total_length += absorb;
+      CHECK_TOTAL_LENGTH (predecessor);
       delete_interval (i);
       return predecessor;
     }
@@ -1540,6 +1569,7 @@ merge_interval_left (i)
 
       predecessor = INTERVAL_PARENT (predecessor);
       predecessor->total_length -= absorb;
+      CHECK_TOTAL_LENGTH (predecessor);
     }
 
   /* This must be the leftmost or first interval and cannot
@@ -2354,6 +2384,7 @@ copy_intervals (tree, start, length)
   new->position = 0;
   got = (LENGTH (i) - (start - i->position));
   new->total_length = length;
+  CHECK_TOTAL_LENGTH (new);
   copy_properties (i, new);
 
   t = new;
@@ -2440,6 +2471,13 @@ set_intervals_multibyte_1 (i, multi_flag, start, start_byte, end, end_byte)
     i->total_length = end - start;
   else
     i->total_length = end_byte - start_byte;
+  CHECK_TOTAL_LENGTH (i);
+
+  if (TOTAL_LENGTH (i) == 0)
+    {
+      delete_interval (i);
+      return;
+    }
 
   /* Recursively fix the length of the subintervals.  */
   if (i->left)
@@ -2448,8 +2486,23 @@ set_intervals_multibyte_1 (i, multi_flag, start, start_byte, end, end_byte)
 
       if (multi_flag)
         {
+          int temp;
           left_end_byte = start_byte + LEFT_TOTAL_LENGTH (i);
           left_end = BYTE_TO_CHAR (left_end_byte);
+
+          temp = CHAR_TO_BYTE (left_end);
+
+          /* If LEFT_END_BYTE is in the middle of a character,
+             adjust it and LEFT_END to a char boundary.  */ 
+          if (left_end_byte > temp)
+            {
+              left_end_byte = temp;
+            }
+          if (left_end_byte < temp)
+            {
+              left_end--;
+              left_end_byte = CHAR_TO_BYTE (left_end);
+            }
         }
       else
         {
@@ -2466,8 +2519,24 @@ set_intervals_multibyte_1 (i, multi_flag, start, start_byte, end, end_byte)
 
       if (multi_flag)
         {
+          int temp;
+
           right_start_byte = end_byte - RIGHT_TOTAL_LENGTH (i);
           right_start = BYTE_TO_CHAR (right_start_byte);
+
+          /* If RIGHT_START_BYTE is in the middle of a character,
+             adjust it and RIGHT_START to a char boundary.  */ 
+          temp = CHAR_TO_BYTE (right_start);
+
+          if (right_start_byte < temp)
+            {
+              right_start_byte = temp;
+            }
+          if (right_start_byte > temp)
+            {
+              right_start++;
+              right_start_byte = CHAR_TO_BYTE (right_start);
+            }
         }
       else
         {
@@ -2479,6 +2548,25 @@ set_intervals_multibyte_1 (i, multi_flag, start, start_byte, end, end_byte)
                                  right_start, right_start_byte,
                                  end, end_byte);
     }
+
+  /* Rounding to char boundaries can theoretically ake this interval
+     spurious.  If so, delete one child, and copy its property list
+     to this interval.  */
+  if (LEFT_TOTAL_LENGTH (i) + RIGHT_TOTAL_LENGTH (i) >= TOTAL_LENGTH (i))
+    {
+      if ((i)->left)
+        {
+          (i)->plist = (i)->left->plist;
+          (i)->left->total_length = 0;
+          delete_interval ((i)->left);
+        }
+      else
+        {
+          (i)->plist = (i)->right->plist;
+          (i)->right->total_length = 0;
+          delete_interval ((i)->right);
+        }
+    }
 }
 
 /* Update the intervals of the current buffer