[2.8] Fix bad usage of strncmp - [MOD-6709] (#4484)

* fix parser

(cherry picked from commit 4ea15f1)

* add test

(cherry picked from commit dcadbd9)

---------

Co-authored-by: GuyAv46 <guy.avimor@gmail.com>

src/query_parser/v2/parser.c

@@ -2122,7 +2122,7 @@ yylhsminor.yy119 = yymsp[0].minor.yy119;
         break;
       case 75: /* vector_command ::= TERM param_size modifier ATTRIBUTE */
 {
-  if (!strncasecmp("KNN", yymsp[-3].minor.yy0.s, yymsp[-3].minor.yy0.len)) {
+  if (yymsp[-3].minor.yy0.len == strlen("KNN") && !strncasecmp("KNN", yymsp[-3].minor.yy0.s, yymsp[-3].minor.yy0.len)) {
     yymsp[0].minor.yy0.type = QT_PARAM_VEC;
     yylhsminor.yy119 = NewVectorNode_WithParams(ctx, VECSIM_QT_KNN, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0);
     yylhsminor.yy119->vn.vq->property = rm_strndup(yymsp[-1].minor.yy0.s, yymsp[-1].minor.yy0.len);
@@ -2173,7 +2173,7 @@ yylhsminor.yy119 = yymsp[0].minor.yy119;
         break;
       case 80: /* vector_range_command ::= TERM param_num ATTRIBUTE */
 {
-  if (!strncasecmp("VECTOR_RANGE", yymsp[-2].minor.yy0.s, yymsp[-2].minor.yy0.len)) {
+  if (yymsp[-2].minor.yy0.len == strlen("VECTOR_RANGE") && !strncasecmp("VECTOR_RANGE", yymsp[-2].minor.yy0.s, yymsp[-2].minor.yy0.len)) {
     yymsp[0].minor.yy0.type = QT_PARAM_VEC;
     yylhsminor.yy119 = NewVectorNode_WithParams(ctx, VECSIM_QT_RANGE, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);
   } else {

src/query_parser/v2/parser.y

@@ -977,7 +977,7 @@ query ::= star ARROW LSQB vector_query(B) RSQB ARROW LB attribute_list(C) RB. {
 // Every vector query will have basic command part.
 // It is this rule's job to create the new vector node for the query.
 vector_command(A) ::= TERM(T) param_size(B) modifier(C) ATTRIBUTE(D). {
-  if (!strncasecmp("KNN", T.s, T.len)) {
+  if (T.len == strlen("KNN") && !strncasecmp("KNN", T.s, T.len)) {
     D.type = QT_PARAM_VEC;
     A = NewVectorNode_WithParams(ctx, VECSIM_QT_KNN, &B, &D);
     A->vn.vq->property = rm_strndup(C.s, C.len);
@@ -1019,7 +1019,7 @@ expr(A) ::= modifier(B) COLON LSQB vector_range_command(C) RSQB. {
 }
 
 vector_range_command(A) ::= TERM(T) param_num(B) ATTRIBUTE(C). {
-  if (!strncasecmp("VECTOR_RANGE", T.s, T.len)) {
+  if (T.len == strlen("VECTOR_RANGE") && !strncasecmp("VECTOR_RANGE", T.s, T.len)) {
     C.type = QT_PARAM_VEC;
     A = NewVectorNode_WithParams(ctx, VECSIM_QT_RANGE, &B, &C);
   } else {

tests/pytests/test_vecsim.py

@@ -503,6 +503,7 @@ def test_search_errors():
 
     env.expect('FT.SEARCH', 'idx', '*=>[REDIS 4 @v $b]', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Syntax error')
     env.expect('FT.SEARCH', 'idx', '*=>[KNN str @v $b]', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Syntax error')
+    env.expect('FT.SEARCH', 'idx', '*=>[K 4 @v $b]', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Syntax error')
 
     env.expect('FT.SEARCH', 'idx', '*=>[KNN 2 @v $b]', 'PARAMS', '2', 'b', 'abcdefg').error().contains('Error parsing vector similarity query: query vector blob size (7) does not match index\'s expected size (8).')
     env.expect('FT.SEARCH', 'idx', '*=>[KNN 2 @v $b]', 'PARAMS', '2', 'b', 'abcdefghi').error().contains('Error parsing vector similarity query: query vector blob size (9) does not match index\'s expected size (8).')
@@ -554,6 +555,7 @@ def test_search_errors():
     env.expect('FT.SEARCH', 'idx', '@v:[vector_range 0.1 $b]', 'PARAMS', '2', 'b', 'abcdefg').error().contains('Error parsing vector similarity query: query vector blob size (7) does not match index\'s expected size (8).')
     env.expect('FT.SEARCH', 'idx', '@v:[vector_range 0.1 $b]', 'PARAMS', '2', 'b', 'abcdefghi').error().contains('Error parsing vector similarity query: query vector blob size (9) does not match index\'s expected size (8).')
     env.expect('FT.SEARCH', 'idx', '@bad:[vector_range 0.1 $b]', 'PARAMS', '2', 'b', 'abcdefgh').equal([0])  # wrong field
+    env.expect('FT.SEARCH', 'idx', '@v:[vector 0.1 $b]', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Syntax error')
     env.expect('FT.SEARCH', 'idx', '@v:[vector_range -1 $b]', 'PARAMS', '2', 'b', 'abcdefgh').error().equal('Error parsing vector similarity query: negative radius (-1) given in a range query')
     env.expect('FT.SEARCH', 'idx', '@v:[vector_range 0.1 $b]=>{$yield_distance_as:t}', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Property `t` already exists in schema')
     env.expect('FT.SEARCH', 'idx', '@v:[vector_range 0.1 $b]=>{$yield_distance_as:dist} @v:[vector_range 0.2 $b]=>{$yield_distance_as:dist}', 'PARAMS', '2', 'b', 'abcdefgh').error().contains('Property `dist` specified more than once')