{"record":{"id":"7596025be47c7c92","repo":"elastic/elasticsearch","slug":"invalid-escaped-char-in","errorCode":null,"errorMessage":"Invalid escaped char in [{}]","messagePattern":"Invalid escaped char in \\[(.+?)\\]","errorType":"validation","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/MappingCharFilterFactory.java","lineNumber":76,"sourceCode":"                throw new RuntimeException(\"Invalid Mapping Rule : [\" + rule + \"]\");\n            }\n            String lhs = parseString(m.group(1).trim());\n            String rhs = parseString(m.group(2).trim());\n            if (lhs == null || rhs == null) throw new RuntimeException(\"Invalid Mapping Rule : [\" + rule + \"]. Illegal mapping.\");\n            map.add(lhs, rhs);\n        }\n    }\n\n    char[] out = new char[256];\n\n    private String parseString(String s) {\n        int readPos = 0;\n        int len = s.length();\n        int writePos = 0;\n        while (readPos < len) {\n            char c = s.charAt(readPos++);\n            if (c == '\\\\') {\n                if (readPos >= len) throw new RuntimeException(\"Invalid escaped char in [\" + s + \"]\");\n                c = s.charAt(readPos++);\n                switch (c) {\n                    case '\\\\' -> c = '\\\\';\n                    case 'n' -> c = '\\n';\n                    case 't' -> c = '\\t';\n                    case 'r' -> c = '\\r';\n                    case 'b' -> c = '\\b';\n                    case 'f' -> c = '\\f';\n                    case 'u' -> {\n                        if (readPos + 3 >= len) throw new RuntimeException(\"Invalid escaped char in [\" + s + \"]\");\n                        c = (char) Integer.parseInt(s.substring(readPos, readPos + 4), 16);\n                        readPos += 4;\n                    }\n                }\n            }\n            out[writePos++] = c;\n        }\n        return new String(out, 0, writePos);","sourceCodeStart":58,"sourceCodeEnd":94,"githubUrl":"https://github.com/elastic/elasticsearch/blob/db6a809a667c081ca1dc7500389d26975573215f/modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/MappingCharFilterFactory.java#L58-L94","documentation":"Error \"Invalid escaped char in [{}]\" thrown in elastic/elasticsearch.","triggerScenarios":"Thrown at modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/MappingCharFilterFactory.java:76 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"analyzedSha":"db6a809a667c081ca1dc7500389d26975573215f","analyzedAt":"2026-08-12T01:39:14.192Z","schemaVersion":2},"datasetVersion":"2026-08-12T12:17:08.281Z"}