Changes On Branch purge
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Changes In Branch purge Excluding Merge-Ins

This is equivalent to a diff from f1a480e130 to 501f3e1143

2016-08-02
15:18
Merge the "purge" command onto trunk, even though it is incomplete. check-in: b78a32f43d user: drh tags: trunk
15:17
Add a further warning on the purge command to indicate that it is dicey. That extra warning makes the purge code permissible to add to trunk. Closed-Leaf check-in: 501f3e1143 user: drh tags: purge
14:52
Improved help and remove redundant file listings for the "fossil purge" command. check-in: 2c53d022c3 user: drh tags: purge
14:41
Sync up with the trunk. check-in: 12f8633aa1 user: drh tags: purge
09:10
Corrections to information about running Fossil in a chroot jail. check-in: f1a480e130 user: drh tags: trunk
08:46
Compiler warning fixes. This includes disabling the undocumented FOSSIL_PWREADER feature and upgrading the built-in SQLite. check-in: f35b46d4cb user: drh tags: trunk

Changes to src/name.c.
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  /* Mark private elements */
  db_multi_exec(
   "UPDATE description SET isPrivate=1 WHERE rid IN private"
  );
}

/*
** Print the content of the description table on stdout





*/
int describe_artifacts_to_stdout(const char *zWhere, const char *zLabel){
  Stmt q;
  int cnt = 0;
  describe_artifacts(zWhere);
  db_prepare(&q,
    "SELECT uuid, summary, isPrivate\n"
    "  FROM description\n"
    " ORDER BY ctime, type;"
  );
  while( db_step(&q)==SQLITE_ROW ){
    if( zLabel ){
      fossil_print("%s\n", zLabel);
      zLabel = 0;
    }
    fossil_print("  %.16s %s", db_column_text(&q,0), db_column_text(&q,1));
    if( db_column_int(&q,2) ) fossil_print(" (unpublished)");
    fossil_print("\n");
    cnt++;
  }
  db_finalize(&q);
  db_multi_exec("DELETE FROM description;");
  return cnt;
}

/*
** COMMAND: test-describe-artifacts
**
** Usage: %fossil test-describe-artifacts [--from S] [--count N]







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  /* Mark private elements */
  db_multi_exec(
   "UPDATE description SET isPrivate=1 WHERE rid IN private"
  );
}

/*
** Print the content of the description table on stdout.
**
** The description table is computed using the WHERE clause zWhere if
** the zWhere parameter is not NULL.  If zWhere is NULL, then this
** routine assumes that the description table already exists and is
** populated and merely prints the contents.
*/
int describe_artifacts_to_stdout(const char *zWhere, const char *zLabel){
  Stmt q;
  int cnt = 0;
  if( zWhere!=0 ) describe_artifacts(zWhere);
  db_prepare(&q,
    "SELECT uuid, summary, isPrivate\n"
    "  FROM description\n"
    " ORDER BY ctime, type;"
  );
  while( db_step(&q)==SQLITE_ROW ){
    if( zLabel ){
      fossil_print("%s\n", zLabel);
      zLabel = 0;
    }
    fossil_print("  %.16s %s", db_column_text(&q,0), db_column_text(&q,1));
    if( db_column_int(&q,2) ) fossil_print(" (unpublished)");
    fossil_print("\n");
    cnt++;
  }
  db_finalize(&q);
  if( zWhere!=0 ) db_multi_exec("DELETE FROM description;");
  return cnt;
}

/*
** COMMAND: test-describe-artifacts
**
** Usage: %fossil test-describe-artifacts [--from S] [--count N]
Changes to src/purge.c.
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** manages the graveyard of purged content.
*/
#include "config.h"
#include "purge.h"
#include <assert.h>

/*
** SQL code used to initialize the schema of a bundle.
**
** The purgeevent table contains one entry for each purge event.  For each
** purge event, multiple artifacts might have been removed.  Each removed
** artifact is stored as an entry in the purgeitem table.
**
** The purgeevent and purgeitem tables are not synced, even by the
** "fossil config" command.  They exist only as a backup in case of a







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** manages the graveyard of purged content.
*/
#include "config.h"
#include "purge.h"
#include <assert.h>

/*
** SQL code used to initialize the schema of the graveyard.
**
** The purgeevent table contains one entry for each purge event.  For each
** purge event, multiple artifacts might have been removed.  Each removed
** artifact is stored as an entry in the purgeitem table.
**
** The purgeevent and purgeitem tables are not synced, even by the
** "fossil config" command.  They exist only as a backup in case of a
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@   isPrivate BOOLEAN,         -- True if artifact was originally private
@   sz INT NOT NULL,           -- Uncompressed size of the purged artifact
@   desc TEXT,                 -- Brief description of this artifact
@   data BLOB                  -- Compressed artifact content
@ );
;










/*
** This routine purges multiple artifacts from the repository, transfering
** those artifacts into the PURGEITEM table.
**
** Prior to invoking this routine, the caller must create a (TEMP) table
** named zTab that contains the RID of every artifact to be purged.
**







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@   isPrivate BOOLEAN,         -- True if artifact was originally private
@   sz INT NOT NULL,           -- Uncompressed size of the purged artifact
@   desc TEXT,                 -- Brief description of this artifact
@   data BLOB                  -- Compressed artifact content
@ );
;

/*
** Flags for the purge_artifact_list() function.
*/
#if INTERFACE
#define PURGE_MOVETO_GRAVEYARD  0x0001    /* Move artifacts in graveyard */
#define PURGE_EXPLAIN_ONLY      0x0002    /* Show what would have happened */
#define PURGE_PRINT_SUMMARY     0x0004    /* Print a summary report at end */
#endif

/*
** This routine purges multiple artifacts from the repository, transfering
** those artifacts into the PURGEITEM table.
**
** Prior to invoking this routine, the caller must create a (TEMP) table
** named zTab that contains the RID of every artifact to be purged.
**
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**         (h) BACKLINK
**         (i) ATTACHMENT
**         (j) TICKETCHNG
**    (7) If any ticket artifacts were removed (6j) then rebuild the
**        corresponding ticket entries.  Possibly remove entries from
**        the ticket table.
**
** Stops 1-4 (saving the purged artifacts into the graveyard) are only
** undertaken if the moveToGraveyard flag is true.
*/
int purge_artifact_list(
  const char *zTab,       /* TEMP table containing list of RIDS to be purged */
  const char *zNote,      /* Text of the purgeevent.pnotes field */
  int moveToGraveyard     /* Move purged artifacts into the graveyard */
){
  int peid = 0;                 /* New purgeevent ID */
  Stmt q;                       /* General-use prepared statement */
  char *z;

  assert( g.repositoryOpen );   /* Main database must already be open */
  db_begin_transaction();
  z = sqlite3_mprintf("IN \"%w\"", zTab);
  describe_artifacts(z);
  sqlite3_free(z);











  /* Make sure we are not removing a manifest that is the baseline of some
  ** manifest that is being left behind.  This step is not strictly necessary.
  ** is is just a safety check. */
  if( purge_baseline_out_from_under_delta(zTab) ){
    fossil_fatal("attempt to purge a baseline manifest without also purging "
                 "all of its deltas");







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**         (h) BACKLINK
**         (i) ATTACHMENT
**         (j) TICKETCHNG
**    (7) If any ticket artifacts were removed (6j) then rebuild the
**        corresponding ticket entries.  Possibly remove entries from
**        the ticket table.
**
** Steps 1-4 (saving the purged artifacts into the graveyard) are only
** undertaken if the moveToGraveyard flag is true.
*/
int purge_artifact_list(
  const char *zTab,       /* TEMP table containing list of RIDS to be purged */
  const char *zNote,      /* Text of the purgeevent.pnotes field */
  unsigned purgeFlags     /* zero or more PURGE_* flags */
){
  int peid = 0;                 /* New purgeevent ID */
  Stmt q;                       /* General-use prepared statement */
  char *z;

  assert( g.repositoryOpen );   /* Main database must already be open */
  db_begin_transaction();
  z = sqlite3_mprintf("IN \"%w\"", zTab);
  describe_artifacts(z);
  sqlite3_free(z);
  describe_artifacts_to_stdout(0, 0);

  /* The explain-only flags causes this routine to list the artifacts
  ** that would have been purged but to not actually make any changes
  ** to the repository.
  */
  if( purgeFlags & PURGE_EXPLAIN_ONLY ){
    db_end_transaction(0);
    return 0;
  }

  /* Make sure we are not removing a manifest that is the baseline of some
  ** manifest that is being left behind.  This step is not strictly necessary.
  ** is is just a safety check. */
  if( purge_baseline_out_from_under_delta(zTab) ){
    fossil_fatal("attempt to purge a baseline manifest without also purging "
                 "all of its deltas");
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    content_undelta(rid);
    verify_before_commit(rid);
  }
  db_finalize(&q);

  /* Construct the graveyard and copy the artifacts to be purged into the
  ** graveyard */
  if( moveToGraveyard ){
    db_multi_exec(zPurgeInit /*works-like:"%w%w"*/,
                  db_name("repository"), db_name("repository"));
    db_multi_exec(
      "INSERT INTO purgeevent(ctime,pnotes) VALUES(now(),%Q)", zNote
    );
    peid = db_last_insert_rowid();
    db_prepare(&q, "SELECT rid FROM delta WHERE rid IN \"%w\""







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    content_undelta(rid);
    verify_before_commit(rid);
  }
  db_finalize(&q);

  /* Construct the graveyard and copy the artifacts to be purged into the
  ** graveyard */
  if( purgeFlags & PURGE_MOVETO_GRAVEYARD ){
    db_multi_exec(zPurgeInit /*works-like:"%w%w"*/,
                  db_name("repository"), db_name("repository"));
    db_multi_exec(
      "INSERT INTO purgeevent(ctime,pnotes) VALUES(now(),%Q)", zNote
    );
    peid = db_last_insert_rowid();
    db_prepare(&q, "SELECT rid FROM delta WHERE rid IN \"%w\""
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    ticket_rebuild_entry(db_column_text(&q, 0));
  }
  db_finalize(&q);
  /* db_multi_exec("DROP TABLE \"%w_tickets\"", zTab); */

  /* Mission accomplished */
  db_end_transaction(0);







  return peid;
}

/*
** The TEMP table named zTab contains RIDs for a set of check-ins.
**
** Check to see if any check-in in zTab is a baseline manifest for some







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    ticket_rebuild_entry(db_column_text(&q, 0));
  }
  db_finalize(&q);
  /* db_multi_exec("DROP TABLE \"%w_tickets\"", zTab); */

  /* Mission accomplished */
  db_end_transaction(0);

  if( purgeFlags & PURGE_PRINT_SUMMARY ){
    fossil_print("%d artifacts purged\n",
                  db_int(0, "SELECT count(*) FROM \"%w\";", zTab));
    fossil_print("undoable using \"%s purge undo %d\".\n",
                  g.nameOfExe, peid);
  }
  return peid;
}

/*
** The TEMP table named zTab contains RIDs for a set of check-ins.
**
** Check to see if any check-in in zTab is a baseline manifest for some
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  }
}


/*
** The TEMP table named zTab contains the RIDs for a set of check-in
** artifacts.  Expand this set (by adding new entries to zTab) to include
** all other artifacts that are used the set of check-ins in
** the original list.
**
** If the bExclusive flag is true, then the set is only expanded by
** artifacts that are used exclusively by the check-ins in the set.
** When bExclusive is false, then all artifacts used by the check-ins
** are added even if those artifacts are also used by other check-ins
** not in the set.







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  }
}


/*
** The TEMP table named zTab contains the RIDs for a set of check-in
** artifacts.  Expand this set (by adding new entries to zTab) to include
** all other artifacts that are used by the check-ins in
** the original list.
**
** If the bExclusive flag is true, then the set is only expanded by
** artifacts that are used exclusively by the check-ins in the set.
** When bExclusive is false, then all artifacts used by the check-ins
** are added even if those artifacts are also used by other check-ins
** not in the set.
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}

/*
** COMMAND: purge
**
** The purge command removes content from a repository and stores that content
** in a "graveyard".  The graveyard exists so that content can be recovered
** using the "fossil purge undo" command.













**
**   fossil purge cat UUID...
**
**      Write the content of one or more artifacts in the graveyard onto
**      standard output.
**
**   fossil purge ?checkins? TAGS... ?OPTIONS?
**
**      Move the check-ins identified by TAGS and all of their descendants
**      out of the repository and into the graveyard.  The "checkins"
**      subcommand keyword is optional and can be omitted as long as TAGS
**      does not conflict with any other subcommand.
**
**      If TAGS includes a branch name then it means all the check-ins
**      on the most recent occurrence of that branch.
**


**           --explain         Make no changes, but show what would happen.


**           --dry-run         Make no changes.
**
**   fossil purge list|ls ?-l?
**
**      Show the graveyard of prior purges.  The -l option gives more
**      detail in the output.
**
**   fossil purge obliterate ID...
**
**      Remove one or more purge events from the graveyard.  Once a purge
**      event is obliterated, it can no longer be undone.





**
**   fossil purge undo ID
**
**      Restore the content previously removed by purge ID.
**









** SUMMARY:
**   fossil purge cat UUID...
**   fossil purge [checkins] TAGS... [--explain]


**   fossil purge list
**   fossil purge obliterate ID...

**   fossil purge undo ID

*/
void purge_cmd(void){

  const char *zSubcmd;
  int n;

  Stmt q;

  if( g.argc<3 ) usage("SUBCOMMAND ?ARGS?");
  zSubcmd = g.argv[2];
  db_find_and_open_repository(0,0);
  n = (int)strlen(zSubcmd);














  if( strncmp(zSubcmd, "cat", n)==0 ){
    int i, piid;
    Blob content;
    if( g.argc<4 ) usage("cat UUID...");
    for(i=3; i<g.argc; i++){
      piid = db_int(0, "SELECT piid FROM purgeitem WHERE uuid LIKE '%q%%'",
                       g.argv[i]);
      if( piid==0 ) fossil_fatal("no such item: %s", g.argv[3]);
      purge_extract_item(piid, &content);
      blob_write_to_file(&content, "-");
      blob_reset(&content);
    }
  /* The "checkins" subcommand goes here in alphabetical order, but it must
  ** be moved to the end since it is the default case */

































  }else if( strncmp(zSubcmd, "list", n)==0 || strcmp(zSubcmd,"ls")==0 ){
    int showDetail = find_option("l","l",0)!=0;
    if( !db_table_exists("repository","purgeevent") ) return;
    db_prepare(&q, "SELECT peid, datetime(ctime,'unixepoch',toLocal())"
                   " FROM purgeevent");
    while( db_step(&q)==SQLITE_ROW ){
      fossil_print("%4d on %s\n", db_column_int(&q,0), db_column_text(&q,1));
      if( showDetail ){
        purge_list_event_content(db_column_int(&q,0));
      }
    }
    db_finalize(&q);
  }else if( strncmp(zSubcmd, "obliterate", n)==0 ){
    int i;

    if( g.argc<4 ) usage("obliterate ID...");











    db_begin_transaction();
    for(i=3; i<g.argc; i++){
      int peid = atoi(g.argv[i]);
      if( !db_exists("SELECT 1 FROM purgeevent WHERE peid=%d",peid) ){
        fossil_fatal("no such purge event: %s", g.argv[i]);
      }
      db_multi_exec(
        "DELETE FROM purgeevent WHERE peid=%d;"
        "DELETE FROM purgeitem WHERE peid=%d;",
        peid, peid
      );
    }
    db_end_transaction(0);


  }else if( strncmp(zSubcmd, "undo", n)==0 ){
    int peid;
    if( g.argc!=4 ) usage("undo ID");
    peid = atoi(g.argv[3]);

    db_begin_transaction();
    db_multi_exec(
      "CREATE TEMP TABLE ix("
      "  piid INTEGER PRIMARY KEY,"
      "  srcid INTEGER"
      ");"
      "CREATE INDEX ixsrcid ON ix(srcid);"
      "INSERT INTO ix(piid,srcid) "
      "  SELECT piid, coalesce(srcid,0) FROM purgeitem WHERE peid=%d;",
      peid
    );
    db_multi_exec(
      "DELETE FROM shun"
      " WHERE uuid IN (SELECT uuid FROM purgeitem WHERE peid=%d);",
      peid
    );
    manifest_crosslink_begin();
    purge_item_resurrect(0, 0);
    manifest_crosslink_end(0);
    db_multi_exec("DELETE FROM purgeevent WHERE peid=%d", peid);
    db_multi_exec("DELETE FROM purgeitem WHERE peid=%d", peid);
    db_end_transaction(0);
  }else{
    /* The "checkins" command is the default and so must occur last */
    int explainOnly = find_option("explain",0,0)!=0;
    int dryRun = find_option("dry-run",0,0)!=0;
    int i;
    int vid;
    int nCkin;
    int nArtifact;
    verify_all_options();
    db_begin_transaction();
    i = strncmp(zSubcmd,"checkins",n)==0 ? 3 : 2;
    if( i>=g.argc ) usage("[checkin] TAGS... [--explain]");
    db_multi_exec("CREATE TEMP TABLE ok(rid INTEGER PRIMARY KEY)");
    for(; i<g.argc; i++){
      int r = name_to_typed_rid(g.argv[i], "br");
      compute_descendants(r, 1000000000);
    }
    vid = db_lget_int("checkout",0);
    if( db_exists("SELECT 1 FROM ok WHERE rid=%d",vid) ){

      fossil_fatal("cannot purge the current checkout");
    }
    nCkin = db_int(0, "SELECT count(*) FROM ok");
    find_checkin_associates("ok", 1);
    nArtifact = db_int(0, "SELECT count(*) FROM ok");
    if( explainOnly ){
      describe_artifacts_to_stdout("IN ok", 0);
    }else{
      int peid = purge_artifact_list("ok","",1);
      fossil_print("%d check-ins and %d artifacts purged.\n", nCkin, nArtifact);
      fossil_print("undoable using \"%s purge undo %d\".\n",
                    g.nameOfExe, peid);
    }
    db_end_transaction(explainOnly||dryRun);


  }
}







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}

/*
** COMMAND: purge
**
** The purge command removes content from a repository and stores that content
** in a "graveyard".  The graveyard exists so that content can be recovered
** using the "fossil purge undo" command.  The "fossil purge obliterate"
** command empties the graveyard, making the content unrecoverable.
**
** ==== WARNING: This command can potentially destroy historical data and ====
** ==== leave your repository in a goofy state. Know what you are doing!  ====
** ==== Make a backup of your repository before using this command!       ====
**
** ==== FURTHER WARNING: This command is a work-in-progress and may yet   ====
** ==== contains bugs.                                                    ====
**
**   fossil purge artifacts UUID... ?OPTIONS?
**
**      Move arbitrary artifacts identified by the UUID list into the 
**      graveyard.
**
**   fossil purge cat UUID...
**
**      Write the content of one or more artifacts in the graveyard onto
**      standard output.
**
**   fossil purge checkins TAGS... ?OPTIONS?
**
**      Move the check-ins or branches identified by TAGS and all of 
**      their descendants out of the repository and into the graveyard.



**      If TAGS includes a branch name then it means all the check-ins
**      on the most recent occurrence of that branch.
**
**   fossil purge files NAME ... ?OPTIONS?
**
**      Move all instances of files called NAME into the graveyard.
**      NAME should be the name of the file relative to the root of the
**      repository.  If NAME is a directory, then all files within that
**      directory are moved.
**
**   fossil purge list|ls ?-l?
**
**      Show the graveyard of prior purges.  The -l option gives more
**      detail in the output.
**
**   fossil purge obliterate ID... ?--force?
**
**      Remove one or more purge events from the graveyard.  Once a purge
**      event is obliterated, it can no longer be undone.  The --force
**      option suppresses the confirmation prompt.
**
**   fossil purge tickets NAME ... ?OPTIONS?
**
**      TBD...
**
**   fossil purge undo ID
**
**      Restore the content previously removed by purge ID.
**
**   fossil purge wiki NAME ... ?OPTIONS?
**
**      TBD...
**
** COMMON OPTIONS:
**
**   --explain         Make no changes, but show what would happen.
**   --dry-run         An alias for --explain
**
** SUMMARY:
**   fossil purge artifacts UUID.. [OPTIONS]
**   fossil purge cat UUID...
**   fossil purge checkins TAGS... [OPTIONS]
**   fossil purge files FILENAME... [OPTIONS]
**   fossil purge list
**   fossil purge obliterate ID...
**   fossil purge tickets NAME... [OPTIONS]
**   fossil purge undo ID
**   fossil purge wiki NAME... [OPTIONS]
*/
void purge_cmd(void){
  int purgeFlags = PURGE_MOVETO_GRAVEYARD | PURGE_PRINT_SUMMARY;
  const char *zSubcmd;
  int n;
  int i;
  Stmt q;

  if( g.argc<3 ) usage("SUBCOMMAND ?ARGS?");
  zSubcmd = g.argv[2];
  db_find_and_open_repository(0,0);
  n = (int)strlen(zSubcmd);
  if( find_option("explain",0,0)!=0 || find_option("dry-run",0,0)!=0 ){
    purgeFlags |= PURGE_EXPLAIN_ONLY;
  }
  if( strncmp(zSubcmd, "artifacts", n)==0 ){
    verify_all_options();
    db_begin_transaction();
    db_multi_exec("CREATE TEMP TABLE ok(rid INTEGER PRIMARY KEY)");
    for(i=3; i<g.argc; i++){
      int r = name_to_typed_rid(g.argv[i], "");
      db_multi_exec("INSERT OR IGNORE INTO ok(rid) VALUES(%d);", r);
    }
    describe_artifacts_to_stdout("IN ok", 0);
    purge_artifact_list("ok", "", purgeFlags);
    db_end_transaction(0);
  }else if( strncmp(zSubcmd, "cat", n)==0 ){
    int i, piid;
    Blob content;
    if( g.argc<4 ) usage("cat UUID...");
    for(i=3; i<g.argc; i++){
      piid = db_int(0, "SELECT piid FROM purgeitem WHERE uuid LIKE '%q%%'",
                       g.argv[i]);
      if( piid==0 ) fossil_fatal("no such item: %s", g.argv[3]);
      purge_extract_item(piid, &content);
      blob_write_to_file(&content, "-");
      blob_reset(&content);
    }
  }else if( strncmp(zSubcmd, "checkins", n)==0 ){
    int vid;
    if( find_option("explain",0,0)!=0 || find_option("dry-run",0,0)!=0 ){
      purgeFlags |= PURGE_EXPLAIN_ONLY;
    }
    verify_all_options();
    db_begin_transaction();
    if( g.argc<=3 ) usage("checkins TAGS... [OPTIONS]");
    db_multi_exec("CREATE TEMP TABLE ok(rid INTEGER PRIMARY KEY)");
    for(i=3; i<g.argc; i++){
      int r = name_to_typed_rid(g.argv[i], "br");
      compute_descendants(r, 1000000000);
    }
    vid = db_lget_int("checkout",0);
    if( db_exists("SELECT 1 FROM ok WHERE rid=%d",vid) ){
      fossil_fatal("cannot purge the current checkout");
    }
    find_checkin_associates("ok", 1);
    purge_artifact_list("ok", "", purgeFlags);
    db_end_transaction(0);
  }else if( strncmp(zSubcmd, "files", n)==0 ){
    verify_all_options();
    db_begin_transaction();
    db_multi_exec("CREATE TEMP TABLE ok(rid INTEGER PRIMARY KEY)");
    for(i=3; i<g.argc; i++){
      db_multi_exec(
         "INSERT OR IGNORE INTO ok(rid) "
         "  SELECT fid FROM mlink, filename"
         "   WHERE mlink.fnid=filename.fnid"
         "     AND (filename.name=%Q OR filename.name GLOB '%q/*')",
         g.argv[i], g.argv[i]
      );
    }
    purge_artifact_list("ok", "", purgeFlags);
    db_end_transaction(0);
  }else if( strncmp(zSubcmd, "list", n)==0 || strcmp(zSubcmd,"ls")==0 ){
    int showDetail = find_option("l","l",0)!=0;
    if( !db_table_exists("repository","purgeevent") ) return;
    db_prepare(&q, "SELECT peid, datetime(ctime,'unixepoch',toLocal())"
                   " FROM purgeevent");
    while( db_step(&q)==SQLITE_ROW ){
      fossil_print("%4d on %s\n", db_column_int(&q,0), db_column_text(&q,1));
      if( showDetail ){
        purge_list_event_content(db_column_int(&q,0));
      }
    }
    db_finalize(&q);
  }else if( strncmp(zSubcmd, "obliterate", n)==0 ){
    int i;
    int bForce = find_option("force","f",0)!=0;
    if( g.argc<4 ) usage("obliterate ID...");
    if( !bForce ){
      Blob ans;
      char cReply;
      prompt_user(
         "Obliterating the graveyard will permanently delete information.\n"
         "Changes cannot be undone.  Continue (y/N)? ", &ans);
      cReply = blob_str(&ans)[0];
      if( cReply!='y' && cReply!='Y' ){
        fossil_exit(1);
      }
    }
    db_begin_transaction();
    for(i=3; i<g.argc; i++){
      int peid = atoi(g.argv[i]);
      if( !db_exists("SELECT 1 FROM purgeevent WHERE peid=%d",peid) ){
        fossil_fatal("no such purge event: %s", g.argv[i]);
      }
      db_multi_exec(
        "DELETE FROM purgeevent WHERE peid=%d;"
        "DELETE FROM purgeitem WHERE peid=%d;",
        peid, peid
      );
    }
    db_end_transaction(0);
  }else if( strncmp(zSubcmd, "tickets", n)==0 ){
    fossil_fatal("not yet implemented....");
  }else if( strncmp(zSubcmd, "undo", n)==0 ){
    int peid;
    if( g.argc!=4 ) usage("undo ID");
    peid = atoi(g.argv[3]);
    if( (purgeFlags & PURGE_EXPLAIN_ONLY)==0 ){
      db_begin_transaction();
      db_multi_exec(
        "CREATE TEMP TABLE ix("
        "  piid INTEGER PRIMARY KEY,"
        "  srcid INTEGER"
        ");"
        "CREATE INDEX ixsrcid ON ix(srcid);"
        "INSERT INTO ix(piid,srcid) "
        "  SELECT piid, coalesce(srcid,0) FROM purgeitem WHERE peid=%d;",
        peid
      );
      db_multi_exec(
        "DELETE FROM shun"
        " WHERE uuid IN (SELECT uuid FROM purgeitem WHERE peid=%d);",
        peid
      );
      manifest_crosslink_begin();
      purge_item_resurrect(0, 0);
      manifest_crosslink_end(0);
      db_multi_exec("DELETE FROM purgeevent WHERE peid=%d", peid);
      db_multi_exec("DELETE FROM purgeitem WHERE peid=%d", peid);
      db_end_transaction(0);
















    }


  }else if( strncmp(zSubcmd, "wiki", n)==0 ){
    fossil_fatal("not yet implemented....");






  }else{


    fossil_fatal("unknown subcommand \"%s\".\n"



                 "should be one of:  cat, checkins, files, list, obliterate,"
                 " tickets, undo, wiki", zSubcmd);
  }
}