ext/pdo_odbc: infinite loop / 100% CPU when fetching a large nvarchar(max) via MS ODBC Driver 18 — SQLGetData is called with a 1-byte buffer and the loop never makes progress (distinct from GH-21534)

[chep6915]

Description

pdo_odbc_issue.md

[ODBC][45576][...][SQLGetData.c][237]
Entry:
Statement = 0x909c88000
Column Number = 1
Target Type = 1 SQL_CHAR
Buffer Length = 1
Target Value = 0x106bfb860
StrLen Or Ind = 0x10741a850
[ODBC][45576][...][SQLGetData.c][545]
Exit:[SQL_SUCCESS_WITH_INFO]
Buffer = Indicator = -4
Strlen Or Ind = 0x10741a850 -> -4 (64 bits)

PHP Version

PHP 8.5.8 (cli) (built: Jul  1 2026 03:46:27) (NTS)
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Operating System

macOS 26.5.2 (build 25F84), Apple Silicon / arm64 (Darwin 25.5.0)

[chep6915]

Thank you for the quick diagnosis and fix — the inverted SQL_NO_TOTAL condition matches exactly what we traced (SQLGetData being called with a 1-byte buffer and spinning). Really appreciate the fast turnaround and the regression test.