Highlighter breaks phrases #29561
Description
Elasticsearch version (bin/elasticsearch --version):
6.2.3
Plugins installed: []
JVM version (java -version):
openjdk version "1.8.0_161"
OS version (uname -a if on a Unix-like system):
Linux 5137c3a21142 4.9.87-linuxkit-aufs
Description of the problem including expected versus actual behavior:
Highlighter breaks searched phrases into separate highlights - makes the highlighter results quite annoying to a user. In the example below the expected highlight would look like this:
shuffled off <em>this mortal coil</em>, must give us
Notice, while the Unified highlighter has this issue the FVH highlighter behaves according to the expectation.
Steps to reproduce:
PUT /test
{
"mappings": {
"t": {
"properties": {
"message": {
"type": "text",
"term_vector": "with_positions_offsets"
}
}
}
}
}
POST /test/t/1
{
"message": "What dreams may come, when we have shuffled off this mortal coil, must give us pause."
}
GET /test/_search
{
"version": true,
"query": {
"match_phrase": {
"message": {
"query": "this mortal coil"
}
}
},
"highlight": {
"fields": {
"message": {
"type": "unified",
"fragment_size": 40
}
}
}
}
This results in the following highlighting, which is practically unusable:
"highlight": {
"message": [
"dreams may come, when we have shuffled off <em>this</em>",
"<em>mortal</em> <em>coil</em>, must give us pause."
]
}