Support escapes spaces in search

CHANGELOG.md

@@ -42,6 +42,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 ### Changed
 
 - We changed `ISSNCleanup` into `NormalizeIssn` a `ISSN` formatter. [#13748](https://github.com/JabRef/jabref/issues/13748)
+- The space character in a search field content is now also accepted when escaped. [#13836](https://github.com/JabRef/jabref/pull/13836)
 - We changed Citation Relations tab and gave tab panes more descriptive titles and tooltips. [#13619](https://github.com/JabRef/jabref/issues/13619)
 - We changed the name from Open AI Provider to Open AI (or API compatible). [#13585](https://github.com/JabRef/jabref/issues/13585)
 - We improved the citations relations caching by implementing an offline storage. [#11189](https://github.com/JabRef/jabref/issues/11189)

jablib/src/main/antlr/org/jabref/search/Search.g4

@@ -15,22 +15,22 @@ WS: [ \t\n\r]+ -> skip; // whitespace is ignored/skipped
 LPAREN: '(';
 RPAREN: ')';
 
-EQUAL: '='; // case insensitive contains, semantically the same as CONTAINS
+EQUAL: '=';   // case insensitive contains, semantically the same as CONTAINS
 CEQUAL: '=!'; // case sensitive contains
 
-EEQUAL: '=='; // exact match case insensitive, semantically the same as MATCHES
+EEQUAL: '==';   // exact match case insensitive, semantically the same as MATCHES
 CEEQUAL: '==!'; // exact match case sensitive
 
-REQUAL: '=~'; // regex check case insensitive
+REQUAL: '=~';    // regex check case insensitive
 CREEQUAL: '=~!'; // regex check case sensitive
 
-NEQUAL: '!='; //  negated case insensitive contains
+NEQUAL: '!=';   //  negated case insensitive contains
 NCEQUAL: '!=!'; // negated case sensitive contains
 
-NEEQUAL: '!=='; // negated case insensitive exact match
+NEEQUAL: '!==';   // negated case insensitive exact match
 NCEEQUAL: '!==!'; // negated case sensitive exact match
 
-NREQUAL: '!=~'; // negated regex check case insensitive
+NREQUAL: '!=~';    // negated regex check case insensitive
 NCREEQUAL: '!=~!'; // negated regex check case sensitive
 
 AND: 'AND';
@@ -41,7 +41,7 @@ NOT: 'NOT';
 
 FIELD: [A-Z]([A-Z] | '-' | '_')*;           // field name should allow for - or _
 STRING_LITERAL: '"' ('\\"' | ~["])* '"';    // " should be escaped with a backslash
-TERM: ('\\' [=!~()] | ~[ \t\n\r=!~()])+;    // =!~() should be escaped with a backslash
+TERM: ('\\' [ :=!~()] | ~[ :=!~()\t\r\n])+; // space and :, =, !, ~, (, ) should be escaped with a backslash; \t\r\n cannot be escaped
 
 start
     : EOF

jablib/src/test/java/org/jabref/logic/search/query/SearchQueryTest.java

@@ -12,6 +12,7 @@ public class SearchQueryTest {
     @ParameterizedTest
     @CsvSource({
             "term",
+            "101.1007/JHEP02(2023)082", // invalid DOI but valid search term
             "term1 term2",
             "term1 term2 term3",
             "term1 AND term2",
@@ -23,6 +24,8 @@ public class SearchQueryTest {
             "NOT (term1 AND term2)",
             "\"term\"",
             "\"term1 term2\"",
+            "termpart1\\ termpart2",
+            "termpart1\\:termpart2",
             "Breitenb{\\\"{u}}cher",
             "K{\\'{a}}lm{\\'{a}}n K{\\'{e}}pes",
             "field = value",
@@ -46,6 +49,7 @@ public class SearchQueryTest {
             "t\\~erm",
             "t\\(1\\)erm",
             "t\\\"erm",
+            "t\\ erm",
     })
     public void validSearchQuery(String searchExpression) {
         assertTrue(new SearchQuery(searchExpression).isValid());
@@ -57,6 +61,8 @@ public void validSearchQuery(String searchExpression) {
             "t~erm",
             "t(erm",
             "term AND",
+            "field:value",
+            "field : value",
             "field CONTAINS NOT value",
     })
     public void invalidSearchQuery(String searchExpression) {