xapian-core/tests/api_posdb.cc

   1 /* api_posdb.cc: tests which need a backend with positional information
   2  *
   3  * Copyright 1999,2000,2001 BrightStation PLC
   4  * Copyright 2002 Ananova Ltd
   5  * Copyright 2002,2003,2004,2005,2006,2007,2009,2016 Olly Betts
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  20  * USA
  21  */
  22
  23 #include <config.h>
  24
  25 #include "api_posdb.h"
  26
  27 #include <string>
  28 #include <vector>
  29
  30 using namespace std;
  31
  32 #include <xapian.h>
  33 #include "testsuite.h"
  34 #include "testutils.h"
  35
  36 #include "apitest.h"
  37
  38 /// Simple test of NEAR
  39 DEFINE_TESTCASE(near1, positional) {
  40     Xapian::Database mydb(get_database("apitest_phrase"));
  41     Xapian::Enquire enquire(mydb);
  42     Xapian::Stem stemmer("english");
  43     enquire.set_weighting_scheme(Xapian::BoolWeight());
  44
  45     // make a query
  46     vector<Xapian::Query> subqs;
  47     Xapian::Query q;
  48     subqs.push_back(Xapian::Query(stemmer("phrase")));
  49     subqs.push_back(Xapian::Query(stemmer("fridge")));
  50     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
  51     enquire.set_query(q);
  52
  53     // retrieve the top ten results
  54     Xapian::MSet mymset = enquire.get_mset(0, 10);
  55     mset_expect_order(mymset);
  56
  57     subqs.clear();
  58     subqs.push_back(Xapian::Query(stemmer("phrase")));
  59     subqs.push_back(Xapian::Query(stemmer("near")));
  60     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 2);
  61     enquire.set_query(q);
  62
  63     // retrieve the top ten results
  64     mymset = enquire.get_mset(0, 10);
  65     mset_expect_order(mymset, 3);
  66
  67     subqs.clear();
  68     subqs.push_back(Xapian::Query(stemmer("phrase")));
  69     subqs.push_back(Xapian::Query(stemmer("near")));
  70     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 3);
  71     enquire.set_query(q);
  72
  73     // retrieve the top ten results
  74     mymset = enquire.get_mset(0, 10);
  75     mset_expect_order(mymset, 1, 3);
  76
  77     subqs.clear();
  78     subqs.push_back(Xapian::Query(stemmer("phrase")));
  79     subqs.push_back(Xapian::Query(stemmer("near")));
  80     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 5);
  81     enquire.set_query(q);
  82
  83     // retrieve the top ten results
  84     mymset = enquire.get_mset(0, 10);
  85     mset_expect_order(mymset, 1, 3);
  86
  87     subqs.clear();
  88     subqs.push_back(Xapian::Query(stemmer("phrase")));
  89     subqs.push_back(Xapian::Query(stemmer("near")));
  90     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 6);
  91     enquire.set_query(q);
  92
  93     // retrieve the top ten results
  94     mymset = enquire.get_mset(0, 10);
  95     mset_expect_order(mymset, 1, 2, 3);
  96
  97     subqs.clear();
  98     subqs.push_back(Xapian::Query(stemmer("leave")));
  99     subqs.push_back(Xapian::Query(stemmer("fridge")));
 100     subqs.push_back(Xapian::Query(stemmer("on")));
 101     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 3);
 102     enquire.set_query(q);
 103
 104     // retrieve the top ten results
 105     mymset = enquire.get_mset(0, 10);
 106     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9);
 107
 108     subqs.clear();
 109     subqs.push_back(Xapian::Query(stemmer("leave")));
 110     subqs.push_back(Xapian::Query(stemmer("fridge")));
 111     subqs.push_back(Xapian::Query(stemmer("on")));
 112     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 4);
 113     enquire.set_query(q);
 114
 115     // retrieve the top ten results
 116     mymset = enquire.get_mset(0, 10);
 117     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10);
 118
 119     subqs.clear();
 120     subqs.push_back(Xapian::Query(stemmer("leave")));
 121     subqs.push_back(Xapian::Query(stemmer("fridge")));
 122     subqs.push_back(Xapian::Query(stemmer("on")));
 123     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 5);
 124     enquire.set_query(q);
 125
 126     // retrieve the top ten results
 127     mymset = enquire.get_mset(0, 10);
 128     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10, 11);
 129
 130     subqs.clear();
 131     subqs.push_back(Xapian::Query(stemmer("leave")));
 132     subqs.push_back(Xapian::Query(stemmer("fridge")));
 133     subqs.push_back(Xapian::Query(stemmer("on")));
 134     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 6);
 135     enquire.set_query(q);
 136
 137     // retrieve the top ten results
 138     mymset = enquire.get_mset(0, 10);
 139     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10, 11, 12);
 140
 141     subqs.clear();
 142     subqs.push_back(Xapian::Query(stemmer("leave")));
 143     subqs.push_back(Xapian::Query(stemmer("fridge")));
 144     subqs.push_back(Xapian::Query(stemmer("on")));
 145     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 7);
 146     enquire.set_query(q);
 147
 148     // retrieve the top twenty results
 149     mymset = enquire.get_mset(0, 20);
 150     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
 151
 152     subqs.clear();
 153     subqs.push_back(Xapian::Query(stemmer("leave")));
 154     subqs.push_back(Xapian::Query(stemmer("fridge")));
 155     subqs.push_back(Xapian::Query(stemmer("on")));
 156     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 8);
 157     enquire.set_query(q);
 158
 159     // retrieve the top twenty results
 160     mymset = enquire.get_mset(0, 20);
 161     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14);
 162
 163     subqs.clear();
 164     subqs.push_back(Xapian::Query(stemmer("leave")));
 165     subqs.push_back(Xapian::Query(stemmer("fridge")));
 166     subqs.push_back(Xapian::Query(stemmer("on")));
 167     // test really large window size
 168     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 999999999);
 169     enquire.set_query(q);
 170
 171     // retrieve the top twenty results
 172     mymset = enquire.get_mset(0, 20);
 173     mset_expect_order(mymset, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14);
 174
 175     return true;
 176 }
 177
 178 /// Test NEAR over operators
 179 DEFINE_TESTCASE(near2, positional) {
 180     Xapian::Database mydb(get_database("apitest_phrase"));
 181     Xapian::Enquire enquire(mydb);
 182     Xapian::Stem stemmer("english");
 183     enquire.set_weighting_scheme(Xapian::BoolWeight());
 184     Xapian::MSet mymset;
 185
 186     // make a query
 187     vector<Xapian::Query> subqs;
 188     Xapian::Query q;
 189     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 190                             Xapian::Query(stemmer("phrase")),
 191                             Xapian::Query(stemmer("near"))));
 192     subqs.push_back(Xapian::Query(stemmer("and")));
 193     TEST_EXCEPTION(Xapian::UnimplementedError,
 194         q = Xapian::Query(q.OP_NEAR, subqs.begin(), subqs.end(), 2);
 195         enquire.set_query(q);
 196
 197         // retrieve the top ten results
 198         mymset = enquire.get_mset(0, 10)
 199     );
 200 #if 0 // Disable until we reimplement this.
 201     mset_expect_order(mymset, 1);
 202
 203     subqs.clear();
 204     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 205                             Xapian::Query(stemmer("phrase")),
 206                             Xapian::Query(stemmer("near"))));
 207     subqs.push_back(Xapian::Query(stemmer("operator")));
 208     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 2);
 209     enquire.set_query(q);
 210
 211     // retrieve the top ten results
 212     mymset = enquire.get_mset(0, 10);
 213     mset_expect_order(mymset, 2);
 214
 215     subqs.clear();
 216     subqs.push_back(Xapian::Query(stemmer("operator")));
 217     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 218                             Xapian::Query(stemmer("phrase")),
 219                             Xapian::Query(stemmer("near"))));
 220     q = Xapian::Query(Xapian::Query::OP_NEAR, subqs.begin(), subqs.end(), 2);
 221     enquire.set_query(q);
 222
 223     // retrieve the top ten results
 224     mymset = enquire.get_mset(0, 10);
 225     mset_expect_order(mymset, 2);
 226 #endif
 227
 228     return true;
 229 }
 230
 231 /// Simple test of PHRASE
 232 DEFINE_TESTCASE(phrase1, positional) {
 233     Xapian::Database mydb(get_database("apitest_phrase"));
 234     Xapian::Enquire enquire(mydb);
 235     Xapian::Stem stemmer("english");
 236     enquire.set_weighting_scheme(Xapian::BoolWeight());
 237
 238     // make a query
 239     vector<Xapian::Query> subqs;
 240     Xapian::Query q;
 241     subqs.push_back(Xapian::Query(stemmer("phrase")));
 242     subqs.push_back(Xapian::Query(stemmer("fridge")));
 243     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 244     enquire.set_query(q);
 245
 246     // retrieve the top ten results
 247     Xapian::MSet mymset = enquire.get_mset(0, 10);
 248     mset_expect_order(mymset);
 249
 250     subqs.clear();
 251     subqs.push_back(Xapian::Query(stemmer("phrase")));
 252     subqs.push_back(Xapian::Query(stemmer("near")));
 253     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 254     enquire.set_query(q);
 255
 256     // retrieve the top ten results
 257     mymset = enquire.get_mset(0, 10);
 258     mset_expect_order(mymset);
 259
 260     subqs.clear();
 261     subqs.push_back(Xapian::Query(stemmer("phrase")));
 262     subqs.push_back(Xapian::Query(stemmer("near")));
 263     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 3);
 264     enquire.set_query(q);
 265
 266     // retrieve the top ten results
 267     mymset = enquire.get_mset(0, 10);
 268     mset_expect_order(mymset, 1);
 269
 270     subqs.clear();
 271     subqs.push_back(Xapian::Query(stemmer("phrase")));
 272     subqs.push_back(Xapian::Query(stemmer("near")));
 273     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 5);
 274     enquire.set_query(q);
 275
 276     // retrieve the top ten results
 277     mymset = enquire.get_mset(0, 10);
 278     mset_expect_order(mymset, 1);
 279
 280     subqs.clear();
 281     subqs.push_back(Xapian::Query(stemmer("phrase")));
 282     subqs.push_back(Xapian::Query(stemmer("near")));
 283     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 6);
 284     enquire.set_query(q);
 285
 286     // retrieve the top ten results
 287     mymset = enquire.get_mset(0, 10);
 288     mset_expect_order(mymset, 1, 2);
 289
 290     subqs.clear();
 291     subqs.push_back(Xapian::Query(stemmer("leave")));
 292     subqs.push_back(Xapian::Query(stemmer("fridge")));
 293     subqs.push_back(Xapian::Query(stemmer("on")));
 294     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 3);
 295     enquire.set_query(q);
 296
 297     // retrieve the top ten results
 298     mymset = enquire.get_mset(0, 10);
 299     mset_expect_order(mymset, 4);
 300
 301     subqs.clear();
 302     subqs.push_back(Xapian::Query(stemmer("leave")));
 303     subqs.push_back(Xapian::Query(stemmer("fridge")));
 304     subqs.push_back(Xapian::Query(stemmer("on")));
 305     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 4);
 306     enquire.set_query(q);
 307
 308     // retrieve the top ten results
 309     mymset = enquire.get_mset(0, 10);
 310     mset_expect_order(mymset, 4);
 311
 312     subqs.clear();
 313     subqs.push_back(Xapian::Query(stemmer("leave")));
 314     subqs.push_back(Xapian::Query(stemmer("fridge")));
 315     subqs.push_back(Xapian::Query(stemmer("on")));
 316     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 5);
 317     enquire.set_query(q);
 318
 319     // retrieve the top ten results
 320     mymset = enquire.get_mset(0, 10);
 321     mset_expect_order(mymset, 4);
 322
 323     subqs.clear();
 324     subqs.push_back(Xapian::Query(stemmer("leave")));
 325     subqs.push_back(Xapian::Query(stemmer("fridge")));
 326     subqs.push_back(Xapian::Query(stemmer("on")));
 327     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 6);
 328     enquire.set_query(q);
 329
 330     // retrieve the top ten results
 331     mymset = enquire.get_mset(0, 10);
 332     mset_expect_order(mymset, 4);
 333
 334     subqs.clear();
 335     subqs.push_back(Xapian::Query(stemmer("leave")));
 336     subqs.push_back(Xapian::Query(stemmer("fridge")));
 337     subqs.push_back(Xapian::Query(stemmer("on")));
 338     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 7);
 339     enquire.set_query(q);
 340
 341     // retrieve the top twenty results
 342     mymset = enquire.get_mset(0, 20);
 343     mset_expect_order(mymset, 4);
 344
 345     subqs.clear();
 346     subqs.push_back(Xapian::Query(stemmer("leave")));
 347     subqs.push_back(Xapian::Query(stemmer("fridge")));
 348     subqs.push_back(Xapian::Query(stemmer("on")));
 349     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 8);
 350     enquire.set_query(q);
 351
 352     // retrieve the top 20 results
 353     mymset = enquire.get_mset(0, 20);
 354     mset_expect_order(mymset, 4);
 355
 356     // test really large window size
 357     subqs.clear();
 358     subqs.push_back(Xapian::Query(stemmer("leave")));
 359     subqs.push_back(Xapian::Query(stemmer("fridge")));
 360     subqs.push_back(Xapian::Query(stemmer("on")));
 361     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 999999999);
 362     enquire.set_query(q);
 363
 364     // retrieve the top 20 results
 365     mymset = enquire.get_mset(0, 20);
 366     mset_expect_order(mymset, 4);
 367
 368     // regression test (was matching doc 15, should fail)
 369     subqs.clear();
 370     subqs.push_back(Xapian::Query(stemmer("first")));
 371     subqs.push_back(Xapian::Query(stemmer("second")));
 372     subqs.push_back(Xapian::Query(stemmer("third")));
 373     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 9);
 374     enquire.set_query(q);
 375
 376     // retrieve the top ten results
 377     mymset = enquire.get_mset(0, 10);
 378     mset_expect_order(mymset);
 379
 380     // regression test (should match doc 15, make sure still does with fix)
 381     subqs.clear();
 382     subqs.push_back(Xapian::Query(stemmer("first")));
 383     subqs.push_back(Xapian::Query(stemmer("second")));
 384     subqs.push_back(Xapian::Query(stemmer("third")));
 385     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 10);
 386     enquire.set_query(q);
 387
 388     // retrieve the top ten results
 389     mymset = enquire.get_mset(0, 10);
 390     mset_expect_order(mymset, 15);
 391
 392     // regression test (phrase matching was getting order wrong when
 393     // build_and_tree reordered vector of PostLists)
 394     subqs.clear();
 395     subqs.push_back(Xapian::Query(stemmer("milk")));
 396     subqs.push_back(Xapian::Query(stemmer("rare")));
 397     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 398     enquire.set_query(q);
 399
 400     // retrieve the top ten results
 401     mymset = enquire.get_mset(0, 10);
 402     mset_expect_order(mymset, 16);
 403
 404     // regression test (phrase matching was getting order wrong when
 405     // build_and_tree reordered vector of PostLists)
 406     subqs.clear();
 407     subqs.push_back(Xapian::Query(stemmer("rare")));
 408     subqs.push_back(Xapian::Query(stemmer("milk")));
 409     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 410     enquire.set_query(q);
 411
 412     // retrieve the top ten results
 413     mymset = enquire.get_mset(0, 10);
 414     mset_expect_order(mymset, 17);
 415
 416     return true;
 417 }
 418
 419 /// Test PHRASE over operators
 420 DEFINE_TESTCASE(phrase2, positional) {
 421     Xapian::Database mydb(get_database("apitest_phrase"));
 422     Xapian::Enquire enquire(mydb);
 423     Xapian::Stem stemmer("english");
 424     enquire.set_weighting_scheme(Xapian::BoolWeight());
 425     Xapian::MSet mymset;
 426
 427     // make a query
 428     vector<Xapian::Query> subqs;
 429     Xapian::Query q;
 430     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 431                             Xapian::Query(stemmer("phrase")),
 432                             Xapian::Query(stemmer("near"))));
 433     subqs.push_back(Xapian::Query(stemmer("and")));
 434     TEST_EXCEPTION(Xapian::UnimplementedError,
 435         q = Xapian::Query(q.OP_PHRASE, subqs.begin(), subqs.end(), 2);
 436         enquire.set_query(q);
 437
 438         // retrieve the top ten results
 439         mymset = enquire.get_mset(0, 10)
 440     );
 441 #if 0 // Disable until we reimplement this.
 442     mset_expect_order(mymset);
 443
 444     subqs.clear();
 445     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 446                             Xapian::Query(stemmer("phrase")),
 447                             Xapian::Query(stemmer("near"))));
 448     subqs.push_back(Xapian::Query(stemmer("operator")));
 449     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 450     enquire.set_query(q);
 451
 452     // retrieve the top ten results
 453     mymset = enquire.get_mset(0, 10);
 454     mset_expect_order(mymset, 2);
 455
 456     subqs.clear();
 457     subqs.push_back(Xapian::Query(stemmer("operator")));
 458     subqs.push_back(Xapian::Query(Xapian::Query::OP_AND,
 459                             Xapian::Query(stemmer("phrase")),
 460                             Xapian::Query(stemmer("near"))));
 461     q = Xapian::Query(Xapian::Query::OP_PHRASE, subqs.begin(), subqs.end(), 2);
 462     enquire.set_query(q);
 463
 464     // retrieve the top ten results
 465     mymset = enquire.get_mset(0, 10);
 466     mset_expect_order(mymset);
 467 #endif
 468
 469     return true;
 470 }
 471
 472 /// Test getting position lists from databases
 473 DEFINE_TESTCASE(poslist1, positional) {
 474     Xapian::Database mydb(get_database("apitest_poslist"));
 475
 476     Xapian::Stem stemmer("english");
 477     string term = stemmer("sponge");
 478
 479     Xapian::PositionIterator pli = mydb.positionlist_begin(2, term);
 480
 481     TEST(pli != mydb.positionlist_end(2, term));
 482     TEST(*pli == 1);
 483     pli++;
 484     TEST(pli != mydb.positionlist_end(2, term));
 485     TEST(*pli == 2);
 486     pli++;
 487     TEST(pli != mydb.positionlist_end(2, term));
 488     TEST(*pli == 3);
 489     pli++;
 490     TEST(pli != mydb.positionlist_end(2, term));
 491     TEST(*pli == 5);
 492     pli++;
 493     TEST(pli != mydb.positionlist_end(2, term));
 494     TEST(*pli == 8);
 495     pli++;
 496     TEST(pli != mydb.positionlist_end(2, term));
 497     TEST(*pli == 13);
 498     pli++;
 499     TEST(pli != mydb.positionlist_end(2, term));
 500     TEST(*pli == 21);
 501     pli++;
 502     TEST(pli != mydb.positionlist_end(2, term));
 503     TEST(*pli == 34);
 504     pli++;
 505     TEST(pli == mydb.positionlist_end(2, term));
 506
 507     return true;
 508 }
 509
 510 DEFINE_TESTCASE(poslist2, positional && writable) {
 511     Xapian::WritableDatabase db = get_writable_database();
 512
 513     Xapian::Document doc;
 514     doc.add_term("nopos");
 515     Xapian::docid did = db.add_document(doc);
 516
 517     // Check what happens when term doesn't exist - should give an empty list.
 518     // Threw RangeError in Xapian < 1.1.0,
 519     TEST_EQUAL(db.positionlist_begin(did, "nosuchterm"),
 520                db.positionlist_end(did, "nosuchterm"));
 521
 522     // Check what happens when the document doesn't even exist - should give
 523     // an empty list.  Threw DocNotFoundError in Xapian < 1.1.0.
 524     TEST_EQUAL(db.positionlist_begin(123, "nosuchterm"),
 525                db.positionlist_end(123, "nosuchterm"));
 526
 527     TEST_EQUAL(db.positionlist_begin(did, "nopos"),
 528                db.positionlist_end(did, "nopos"));
 529
 530     Xapian::Document doc2 = db.get_document(did);
 531
 532     Xapian::TermIterator term = doc2.termlist_begin();
 533
 534     {
 535         Xapian::PositionIterator i = term.positionlist_begin();
 536         TEST_EQUAL(i, term.positionlist_end());
 537     }
 538
 539     Xapian::Document doc3;
 540     doc3.add_posting("hadpos", 1);
 541     Xapian::docid did2 = db.add_document(doc3);
 542
 543     Xapian::Document doc4 = db.get_document(did2);
 544     doc4.remove_posting("hadpos", 1);
 545     db.replace_document(did2, doc4);
 546
 547     {
 548         Xapian::PositionIterator i = db.positionlist_begin(did2, "hadpos");
 549         TEST_EQUAL(i, db.positionlist_end(did2, "hadpos"));
 550     }
 551
 552     db.delete_document(did);
 553     // Check what happens when the document doesn't exist (but once did).
 554     TEST_EQUAL(db.positionlist_begin(did, "nosuchterm"),
 555                db.positionlist_end(did, "nosuchterm"));
 556
 557     return true;
 558 }
 559
 560 /// Test playing with a positionlist, testing skip_to in particular.
 561 /// (used to be quartztest's test_positionlist1).
 562 DEFINE_TESTCASE(poslist3, positional && writable) {
 563     Xapian::WritableDatabase db = get_writable_database();
 564
 565     Xapian::Document document;
 566     document.add_posting("foo", 5);
 567     document.add_posting("foo", 8);
 568     document.add_posting("foo", 10);
 569     document.add_posting("foo", 12);
 570     db.add_document(document);
 571
 572     Xapian::PositionIterator pl = db.positionlist_begin(1, "foo");
 573     Xapian::PositionIterator pl_end = db.positionlist_end(1, "foo");
 574
 575     TEST(pl != pl_end);
 576     TEST_EQUAL(*pl, 5);
 577     ++pl;
 578     TEST(pl != pl_end);
 579     TEST_EQUAL(*pl, 8);
 580     ++pl;
 581     TEST(pl != pl_end);
 582     TEST_EQUAL(*pl, 10);
 583     ++pl;
 584     TEST(pl != pl_end);
 585     TEST_EQUAL(*pl, 12);
 586     ++pl;
 587     TEST(pl == pl_end);
 588
 589     pl = db.positionlist_begin(1, "foo");
 590     pl.skip_to(5);
 591     TEST(pl != pl_end);
 592     TEST_EQUAL(*pl, 5);
 593
 594     pl.skip_to(9);
 595     TEST(pl != pl_end);
 596     TEST_EQUAL(*pl, 10);
 597
 598     ++pl;
 599     TEST(pl != pl_end);
 600     TEST_EQUAL(*pl, 12);
 601
 602     pl.skip_to(12);
 603     TEST(pl != pl_end);
 604     TEST_EQUAL(*pl, 12);
 605
 606     pl.skip_to(13);
 607     TEST(pl == pl_end);
 608
 609     return true;
 610 }
 611
 612 // Regression test - in 0.9.4 (and many previous versions) you couldn't get a
 613 // PositionIterator from a TermIterator from Database::termlist_begin().
 614 //
 615 // Also test that positionlist_count() is implemented for this case, which it
 616 // wasn't in 1.0.2 and earlier.
 617 DEFINE_TESTCASE(positfromtermit1, positional) {
 618     Xapian::Database db(get_database("apitest_phrase"));
 619     Xapian::TermIterator t(db.termlist_begin(7));
 620     TEST_NOT_EQUAL(t, db.termlist_end(7));
 621     Xapian::PositionIterator p = t.positionlist_begin();
 622     TEST_NOT_EQUAL(p, t.positionlist_end());
 623
 624     try {
 625         TEST_EQUAL(t.positionlist_count(), 1);
 626         t.skip_to("on");
 627         TEST_NOT_EQUAL(t, db.termlist_end(7));
 628         TEST_EQUAL(t.positionlist_count(), 2);
 629     } catch (const Xapian::UnimplementedError &) {
 630         SKIP_TEST("TermList::positionlist_count() not yet implemented for this backend");
 631     }
 632
 633     return true;
 634 }