Fossil

        g.zLocalDbName = mprintf("%s", zPwd);
        zPwd[n] = 0;
        while( n>0 && zPwd[n-1]=='/' ){
          n--;
          zPwd[n] = 0;
        }
        g.zLocalRoot = mprintf("%s/", zPwd);
        g.localOpen = db_lget_int("checkout", -1);
        db_open_repository(zDbName);
        return 1;
      }
    }
    if( bRootOnly ) break;
    n--;
    while( n>1 && zPwd[n]!='/' ){ n--; }

**
** This file contains code used to resolved user-supplied object names.
*/
#include "config.h"
#include "name.h"
#include <assert.h>

#if INTERFACE
/*
** An upper boundary on RIDs, provided in order to be able to
** distinguish real RID values from RID_CKOUT and any future
** RID_... values.
*/
#define RID_MAX        0x7ffffff0
/*
** A "magic" RID representing the current checkout in some contexts.
*/
#define RID_CKOUT      (RID_MAX+1)
#endif

/*
** Return TRUE if the string begins with something that looks roughly
** like an ISO date/time string.  The SQLite date/time functions will
** have the final say-so about whether or not the date/time string is
** well-formed.
*/
int fossil_isdate(const char *z){

    "  par(pid, ex, cnt) as ("
    "    SELECT pid, EXISTS(SELECT 1 FROM tagxref"
    "                        WHERE tagid=%d AND tagtype>0"
    "                          AND value=%Q AND rid=plink.pid), 1"
    "    FROM plink WHERE cid=%d AND isprim"
    "    UNION ALL "
    "    SELECT plink.pid, EXISTS(SELECT 1 FROM tagxref "
    "                              WHERE tagid=%d AND tagtype>0"
    "                                AND value=%Q AND rid=plink.pid),"
    "           1+par.cnt"
    "      FROM plink, par"
    "     WHERE cid=par.pid AND isprim AND par.ex "
    "     LIMIT 100000 "
    "  )"
    " SELECT pid FROM par WHERE ex>=%d ORDER BY cnt DESC LIMIT 1",
    TAG_BRANCH, zBr, ans, TAG_BRANCH, zBr, eType%2
  );
  fossil_free(zBr);
  rc = db_step(&q);
  if( rc==SQLITE_ROW ){
    ans = db_column_int(&q, 0);
  }
  db_finalize(&q);
  if( eType==2 && ans>0 ){
    zBr = branch_of_rid(ans);
    ans = compute_youngest_ancestor_in_branch(rid, zBr);
    fossil_free(zBr);
  }
  return ans;
}

/*
** Find the RID of the most recent object with symbolic tag zTag
** and having a type that matches zType.
**
** Return 0 if there are no matches.
**
** This is a tricky query to do efficiently.
** If the tag is very common (ex: "trunk") then
** we want to use the query identified below as Q1 - which searching
** the most recent EVENT table entries for the most recent with the tag.
** But if the tag is relatively scarce (anything other than "trunk", basically)
** then we want to do the indexed search show below as Q2.
*/
static int most_recent_event_with_tag(const char *zTag, const char *zType){

**
** The zType parameter specifies the type of artifact: ci, t, w, e, g, f.
** If zType is NULL or "" or "*" then any type of artifact will serve.
** If zType is "br" then find the first check-in of the named branch
** rather than the last.
**
** zType is "ci" in most use cases since we are usually searching for
** a check-in. A value of "ci+" works like "ci" but adds these
** semantics: if zTag is "ckout" and a checkout is open, "ci+" causes
** RID_CKOUT to be returned, in which case g.localOpen will hold the
** RID of the checkout. Conversely, passing in the hash, or another
** symbolic name of the local checkout version, will always result in
** its RID being returned.
**
** Note that the input zTag for types "t" and "e" is the artifact hash of
** the ticket-change or technote-change artifact, not the randomly generated
** hexadecimal identifier assigned to tickets and events.  Those identifiers
** live in a separate namespace.
*/
int symbolic_name_to_rid(const char *zTag, const char *zType){

  int rid = 0;
  int nTag;
  int i;
  int startOfBranch = 0;
  const char *zXTag;     /* zTag with optional [...] removed */
  int nXTag;             /* Size of zXTag */
  const char *zDate;     /* Expanded date-time string */
  int isCheckin = 0;     /* zType==ci = 1, zType==ci+ = 2 */

  if( zType==0 || zType[0]==0 ){
    zType = "*";
  }else if( zType[0]=='b' ){
    zType = "ci";
    startOfBranch = 1;
  }
  if( zTag==0 || zTag[0]==0 ) return 0;
  else if( 'c'==zType[0] ){
    if( fossil_strcmp(zType,"ci")==0 ){
      isCheckin = 1;
    }else if( fossil_strcmp(zType,"ci+")==0 ){
      isCheckin = 2;
      zType = "ci";
    }
  }

  /* special keyword: "tip" */
  if( fossil_strcmp(zTag, "tip")==0 && (zType[0]=='*' || isCheckin!=0) ){
    rid = db_int(0,
      "SELECT objid"
      "  FROM event"
      " WHERE type='ci'"
      " ORDER BY event.mtime DESC"
    );
    if( rid ) return rid;
  }

  /* special keywords: "prev", "previous", "current", "ckout", and
  ** "next" */
  if( g.localOpen>0 && (zType[0]=='*' || isCheckin!=0) ){
    const int vid = g.localOpen;
    if( fossil_strcmp(zTag, "current")==0 ){
      rid = vid;
    }else if( fossil_strcmp(zTag, "prev")==0
              || fossil_strcmp(zTag, "previous")==0 ){
      rid = db_int(0, "SELECT pid FROM plink WHERE cid=%d AND isprim", vid);
    }else if( fossil_strcmp(zTag, "next")==0 ){
      rid = db_int(0, "SELECT cid FROM plink WHERE pid=%d"
                      "  ORDER BY isprim DESC, mtime DESC", vid);
    }else if( isCheckin>1 && fossil_strcmp(zTag, "ckout")==0 ){
      rid = RID_CKOUT;
    }
    if( rid ) return rid;
  }

  /* Date and times */
  if( memcmp(zTag, "date:", 5)==0 ){
    zDate = fossil_expand_datetime(&zTag[5],0);

  if( nTag>4
   && is_trailing_punct(zTag[nTag-1])
   && !is_trailing_punct(zTag[nTag-2])
  ){
    char *zNew = fossil_strndup(zTag, nTag-1);
    rid = symbolic_name_to_rid(zNew,zType);
    fossil_free(zNew);
  }else
  if( nTag>5
   && is_trailing_punct(zTag[nTag-1])
   && is_trailing_punct(zTag[nTag-2])
   && !is_trailing_punct(zTag[nTag-3])
  ){
    char *zNew = fossil_strndup(zTag, nTag-2);
    rid = symbolic_name_to_rid(zNew,zType);

** negative value is returned. On success the rid is returned and
** pUuid (if it is not NULL) is set to a newly-allocated string,
** the full hash, which must eventually be free()d by the caller.
*/
int name_to_uuid2(const char *zName, const char *zType, char **pUuid){
  int rid = symbolic_name_to_rid(zName, zType);
  if((rid>0) && pUuid){
    *pUuid = (rid<RID_MAX)
      ? db_text(NULL, "SELECT uuid FROM blob WHERE rid=%d", rid)
      : NULL;
  }
  return rid;
}


/*
** name_collisions searches through events, blobs, and tickets for

  }
  return c;
}

/*
** COMMAND: test-name-to-id
**
** Usage:  %fossil test-name-to-id [--count N] [--type ARTIFACT_TYPE] NAME
**
** Convert a NAME to a full artifact ID.  Repeat the conversion N
** times (for timing purposes) if the --count option is given.
*/
void test_name_to_id(void){
  int i;
  int n = 0;
  Blob name;
  const char *zType;

  db_must_be_within_tree();
  if( (zType = find_option("type","t",1))==0 ){
    zType = "*";
  }
  for(i=2; i<g.argc; i++){
    if( strcmp(g.argv[i],"--count")==0 && i+1<g.argc ){
      i++;
      n = atoi(g.argv[i]);
      continue;
    }
    do{
      blob_init(&name, g.argv[i], -1);
      fossil_print("%s -> ", g.argv[i]);
      if( name_to_uuid(&name, 1, zType) ){
        fossil_print("ERROR: %s\n", g.zErrMsg);
        fossil_error_reset();
      }else{
        fossil_print("%s\n", blob_buffer(&name));
      }
      blob_reset(&name);
    }while( n-- > 0 );