{"record":{"id":"4f4787b08580b7d6","repo":"earendil-works/pi","slug":"cannot-preserve-unchanged-lines-because-the-base-c","errorCode":null,"errorMessage":"Cannot preserve unchanged lines because the base content has a different line count.","messagePattern":"Cannot preserve unchanged lines because the base content has a different line count\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/agent/src/harness/tools/edit-diff.ts","lineNumber":136,"sourceCode":"/**\n * Apply replacements matched against `baseContent` to `originalContent` while\n * preserving unchanged line blocks from the original.\n *\n * This is useful when `baseContent` is a normalized view of the original. Each\n * replacement is widened to the lines it actually touches, those touched lines\n * are rewritten from the normalized base, and all other lines are copied back\n * from `originalContent`. The actual replacement ranges drive preservation so\n * duplicate normalized lines cannot be aligned to the wrong occurrence.\n */\nexport function applyReplacementsPreservingUnchangedLines(\n\toriginalContent: string,\n\tbaseContent: string,\n\treplacements: TextReplacement[],\n): string {\n\tconst originalLines = splitLinesWithEndings(originalContent);\n\tconst baseLines = getLineSpans(baseContent);\n\tif (originalLines.length !== baseLines.length) {\n\t\tthrow new Error(\"Cannot preserve unchanged lines because the base content has a different line count.\");\n\t}\n\n\tconst groups: Array<{ startLine: number; endLine: number; replacements: TextReplacement[] }> = [];\n\tconst sortedReplacements = [...replacements].sort((a, b) => a.matchIndex - b.matchIndex);\n\tfor (const replacement of sortedReplacements) {\n\t\tconst range = getReplacementLineRange(baseLines, replacement);\n\t\tconst current = groups[groups.length - 1];\n\t\tif (current && range.startLine < current.endLine) {\n\t\t\tcurrent.endLine = Math.max(current.endLine, range.endLine);\n\t\t\tcurrent.replacements.push(replacement);\n\t\t\tcontinue;\n\t\t}\n\t\tgroups.push({ ...range, replacements: [replacement] });\n\t}\n\n\tlet originalLineIndex = 0;\n\tlet result = \"\";\n\tfor (const group of groups) {","sourceCodeStart":118,"sourceCodeEnd":154,"githubUrl":"https://github.com/earendil-works/pi/blob/4af9d21d3b4d664e4a29fcabfec85171077248e3/packages/agent/src/harness/tools/edit-diff.ts#L118-L154","documentation":"Error \"Cannot preserve unchanged lines because the base content has a different line count.\" thrown in earendil-works/pi.","triggerScenarios":"Thrown at packages/agent/src/harness/tools/edit-diff.ts:136 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Re-read the file so the base content line count matches, then retry the edit."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"4af9d21d3b4d664e4a29fcabfec85171077248e3","analyzedAt":"2026-08-24T13:07:14.692Z","schemaVersion":2},"datasetVersion":"2026-08-24T17:17:21.512Z"}