Bug 202240
| Summary: | [patch] fwscanf return EOF instead of ZERO in the event of matching failure | ||||||
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| Product: | Base System | Reporter: | Rajendra <rajendra.sy> | ||||
| Component: | kern | Assignee: | Stephen J. Kiernan <stevek> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Many People | CC: | cem, rajendra.sy, stevek | ||||
| Priority: | --- | Keywords: | patch | ||||
| Version: | CURRENT | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| URL: | https://reviews.freebsd.org/D13288 | ||||||
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A commit references this bug: Author: stevek Date: Wed Dec 6 21:12:24 UTC 2017 New revision: 326635 URL: https://svnweb.freebsd.org/changeset/base/326635 Log: The function fwscanf() return value is wrong when encountering an early matching failure. According to the Open Group documentation for fwscanf: "Upon successful completion, these functions shall return the number of successfully matched and assigned input items; this number can be zero in the event of an early matching failure." Without this change, fwscanf would return EOF in the case of an early matching failure, instead of the proper return value of 0. This change aligns fwscanf(3) with the implementation in fscanf(3). PR: 202240 Submitted by: rajendra.sy@gmail.com Reviewed by: jhb, cem Approved by: sjg (mentor) MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D13288 Changes: head/lib/libc/stdio/vfwscanf.c |
Created attachment 159753 [details] Source file compares fwscanf & fscanf return values The function fwscanf() return value is wrong incase of invalid input character. For example: int ret = fwscanf(fptr, L"j%s", buf); The above call should return ZERO for matching failure. Possible fix: --- a/lib/libc/stdio/vfwscanf.c +++ b/lib/libc/stdio/vfwscanf.c @@ -492,7 +492,7 @@ literal: goto input_failure; if (wi != c) { __ungetwc(wi, fp, locale); - goto input_failure; + goto match_failure; } nread++; continue; The fscanf() function behaves correctly. Compared the source of both functions confirms the return is value is wrong. Attached a source file to reproduce the problem.