Fossil

** merchantability or fitness for a particular purpose.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
** 
** This file implements the undo/redo functionality.
*/
#include "config.h"
#include "undo.h"

    int new_exe;
    int new_link;
    int old_link;
    Blob current;
    Blob new;
    zFullname = mprintf("%s/%s", g.zLocalRoot, zPathname);
    old_link = db_column_int(&q, 3);
    new_link = file_wd_islink(zFullname);
    new_exists = file_wd_size(zFullname)>=0;

    if( new_exists ){
      if( new_link ){
        blob_read_link(&current, zFullname);
      }else{
        blob_read_from_file(&current, zFullname);        
      }
      new_exe = file_wd_isexe(zFullname);
    }else{
      blob_zero(&current);
      new_exe = 0;
    }
    blob_zero(&new);
    old_exists = db_column_int(&q, 1);
    old_exe = db_column_int(&q, 2);

    }else{
      fossil_print("DELETE %s\n", zPathname);
      file_delete(zFullname);
    }
    blob_reset(&new);
    free(zFullname);
    db_finalize(&q);
    db_prepare(&q, 
       "UPDATE undo SET content=:c, existsflag=%d, isExe=%d, isLink=%d,"
             " redoflag=NOT redoflag"
       " WHERE pathname=%Q",
       new_exists, new_exe, new_link, zPathname
    );
    if( new_exists ){
      db_bind_blob(&q, ":c", &current);

/*
** Begin capturing a snapshot that can be undone.
*/
void undo_begin(void){
  int cid;
  const char *zDb = db_name("localdb");
  static const char zSql[] = 
    @ CREATE TABLE "%w".undo(
    @   pathname TEXT UNIQUE,             -- Name of the file
    @   redoflag BOOLEAN,                 -- 0 for undoable.  1 for redoable
    @   existsflag BOOLEAN,               -- True if the file exists
    @   isExe BOOLEAN,                    -- True if the file is executable
    @   isLink BOOLEAN,                   -- True if the file is symlink
    @   content BLOB                      -- Saved content

  db_lset_int("undo_checkout", cid);
  db_lset_int("undo_available", 1);
  db_lset("undo_cmdline", undoCmd);
  undoActive = 1;
}

/*
** Permanently disable undo 
*/
void undo_disable(void){
  undoDisable = 1;
}

/*
** This flag is true if one or more files have changed and have been

    "INSERT OR IGNORE INTO"
    "   undo(pathname,redoflag,existsflag,isExe,isLink,content)"
    " VALUES(%Q,0,%d,%d,%d,:c)",
    zPathname, existsFlag, file_wd_isexe(zFullname), isLink
  );
  if( existsFlag ){
    if( isLink ){
      blob_read_link(&content, zFullname); 
    }else{
      blob_read_from_file(&content, zFullname);
    }
    db_bind_blob(&q, ":c", &content);
  }
  free(zFullname);
  db_step(&q);

**
**    (1) fossil update             (5) fossil stash apply
**    (2) fossil merge              (6) fossil stash drop
**    (3) fossil revert             (7) fossil stash goto
**    (4) fossil stash pop
**
** If FILENAME is specified then restore the content of the named
** file(s) but otherwise leave the update or merge or revert in effect. 
** The redo command undoes the effect of the most recent undo.
**
** If the -n|--dry-run option is present, no changes are made and instead
** the undo or redo command explains what actions the undo or redo would
** have done had the -n|--dry-run been omitted.
**
** A single level of undo/redo is supported.  The undo/redo stack

      );
      while( db_step(&q)==SQLITE_ROW ){
        if( nChng==0 ){
          fossil_print("The following file changes would occur if the "
                       "command above is %sne:\n\n", zCmd);
        }
        nChng++;
        fossil_print("%s %s\n", 
           db_column_int(&q,0) ? "UPDATE" : "DELETE",
           db_column_text(&q, 1)
        );
      }
      db_finalize(&q);
      if( nChng==0 ){
        fossil_print("No file changes would occur with this undo/redo.\n");