Fix a segfault in fts3 that may occur if the snippet, offsets or matchinfo functions are used in a query that does not contain a MATCH clause.

FossilOrigin-Name: 14ab536a96f81595ab8c3dcd4b72075f1a827c8b

ext/fts3/fts3_snippet.c

@@ -926,6 +926,11 @@ void sqlite3Fts3Snippet(
   SnippetFragment aSnippet[4];    /* Maximum of 4 fragments per snippet */
   int nFToken = -1;               /* Number of tokens in each fragment */
 
+  if( !pCsr->pExpr ){
+    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
+    return;
+  }
+
   for(nSnippet=1; 1; nSnippet++){
 
     int iSnip;                    /* Loop counter 0..nSnippet-1 */
@@ -1053,6 +1058,11 @@ void sqlite3Fts3Offsets(
   StrBuffer res = {0, 0, 0};      /* Result string */
   TermOffsetCtx sCtx;             /* Context for fts3ExprTermOffsetInit() */
 
+  if( !pCsr->pExpr ){
+    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
+    return;
+  }
+
   memset(&sCtx, 0, sizeof(sCtx));
   assert( pCsr->isRequireSeek==0 );
 
@@ -1168,7 +1178,12 @@ void sqlite3Fts3Offsets(
 ** Implementation of matchinfo() function.
 */
 void sqlite3Fts3Matchinfo(sqlite3_context *pContext, Fts3Cursor *pCsr){
-  int rc = fts3GetMatchinfo(pCsr);
+  int rc;
+  if( !pCsr->pExpr ){
+    sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
+    return;
+  }
+  rc = fts3GetMatchinfo(pCsr);
   if( rc!=SQLITE_OK ){
     sqlite3_result_error_code(pContext, rc);
   }else{

manifest

@@ -1,8 +1,5 @@
------BEGIN PGP SIGNED MESSAGE-----
-Hash: SHA1
-
-C Make\ssure\sfile\sdescriptors\sare\sclosed\sbefore\sunlinking\sin\sVxWorks.
-D 2010-02-05T18:00:26
+C Fix\sa\ssegfault\sin\sfts3\sthat\smay\soccur\sif\sthe\ssnippet,\soffsets\sor\smatchinfo\sfunctions\sare\sused\sin\sa\squery\sthat\sdoes\snot\scontain\sa\sMATCH\sclause.
+D 2010-02-10T05:33:18
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in c5827ead754ab32b9585487177c93bb00b9497b3
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -67,7 +64,7 @@ F ext/fts3/fts3_hash.c 3c8f6387a4a7f5305588b203fa7c887d753e1f1c
 F ext/fts3/fts3_hash.h 8331fb2206c609f9fc4c4735b9ab5ad6137c88ec
 F ext/fts3/fts3_icu.c ac494aed69835008185299315403044664bda295
 F ext/fts3/fts3_porter.c 7546e4503e286a67fd4f2a82159620e3e9c7a1bc
-F ext/fts3/fts3_snippet.c 67ef70f0e2e18a904b6e9d9cdd045d306f1d2b23
+F ext/fts3/fts3_snippet.c 9cba9a321fbea2e73a2de8cdd0003e4b1717130c
 F ext/fts3/fts3_tokenizer.c 1a49ee3d79cbf0b9386250370d9cbfe4bb89c8ff
 F ext/fts3/fts3_tokenizer.h 13ffd9fcb397fec32a05ef5cd9e0fa659bf3dbd3
 F ext/fts3/fts3_tokenizer1.c b6d86d1d750787db5c168c73da4e87670ed890a1
@@ -408,7 +405,7 @@ F test/fts3malloc.test 059592c4f37ccd30138bbf8e3e5b7982cb5c8f2e
 F test/fts3near.test 2e318ee434d32babd27c167142e2b94ddbab4844
 F test/fts3query.test 154fe4b015fd61af523ee083570a134f508f5be7
 F test/fts3rnd.test 2f5761db9dd92f6fe09d08976ac658ef521846ed
-F test/fts3snippet.test f1f07d82d0deb686dfdd5e16c0c8fe9eebd337d4
+F test/fts3snippet.test 5745ce7270fb754b4f998c6bc33bf843791f6e36
 F test/fts4aa.test 9a9bc506487399c17284fa82a72f16d5ced2910c
 F test/func.test af106ed834001738246d276659406823e35cde7b
 F test/func2.test 772d66227e4e6684b86053302e2d74a2500e1e0f
@@ -789,14 +786,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 27dc5b1c52eaa5f99cf44ee31204f62598fbf011
-R 3ba9a44bc6dc025226dbeec1039229af
-U drh
-Z e7553a909f891032352b25ece0d2bf55
------BEGIN PGP SIGNATURE-----
-Version: GnuPG v1.4.6 (GNU/Linux)
-
-iD8DBQFLbFy+oxKgR168RlERAvi3AJ4iSgHPeSld3G/lZ80D58qvjPpIXgCfdgis
-x5HMC3pHyeLTKGC/N5Wa6sw=
-=LmbB
------END PGP SIGNATURE-----
+P f64b81f13de4875343c752e7183bf61032dc9594
+R 5333db164ef39e64c57fafc741c13181
+U dan
+Z d15835a4ab01775366b26edc0ebe998b

manifest.uuid

@@ -1 +1 @@
-f64b81f13de4875343c752e7183bf61032dc9594
+14ab536a96f81595ab8c3dcd4b72075f1a827c8b

test/fts3snippet.test

@@ -432,7 +432,34 @@ foreach {DO_MALLOC_TEST enc} {
     {2 2 1 3 3 3 6 3 0 0 0 2 3 2}          
     {2 2 1 3 3 3 6 3 0 0 0 2 3 2}
   }]
+
+  # EVIDENCE-OF: R-56101-59725 If used within a SELECT that uses the
+  # "query by rowid" or "linear scan" strategies, then the snippet and
+  # offsets both return an an empty string, and the matchinfo function
+  # returns a blob value zero bytes in size.
+  #
+  set r 1000000                   ;# A rowid that exists in table ft
+  do_select_test $T.10.0 { SELECT rowid FROM ft WHERE rowid = $r } $r
+  do_select_test $T.10.1 {
+    SELECT length(offsets(ft)), typeof(offsets(ft)) FROM ft;
+  } {0 text 0 text 0 text}
+  do_select_test $T.10.2 {
+    SELECT length(offsets(ft)), typeof(offsets(ft)) FROM ft WHERE rowid = $r
+  } {0 text}
+  do_select_test $T.10.3 {
+    SELECT length(snippet(ft)), typeof(snippet(ft)) FROM ft;
+  } {0 text 0 text 0 text}
+  do_select_test $T.10.4 {
+    SELECT length(snippet(ft)), typeof(snippet(ft)) FROM ft WHERE rowid = $r;
+  } {0 text}
+  do_select_test $T.10.5 {
+    SELECT length(matchinfo(ft)), typeof(matchinfo(ft)) FROM ft;
+  } {0 blob 0 blob 0 blob}
+  do_select_test $T.10.6 {
+    SELECT length(matchinfo(ft)), typeof(matchinfo(ft)) FROM ft WHERE rowid = $r
+  } {0 blob}
 }
 
+
 set sqlite_fts3_enable_parentheses 0
 finish_test