refs API: make parse_loose_ref_contents() not set errno
Change the parse_loose_ref_contents() function to stop setting "errno" and failure, and to instead pass up a "failure_errno" via a parameter. This requires changing its callers to do the same. The EINVAL error from parse_loose_ref_contents is used in files-backend to create a custom error message. In untangling this we discovered a tricky edge case. The refs_read_special_head() function was relying on parse_loose_ref_contents() setting EINVAL. By converting it to use "saved_errno" we can migrate away from "errno" in this part of the code entirely, and do away with an existing "save_errno" pattern, its only purpose was to not clobber the "errno" we previously needed at the end of files_read_raw_ref(). Let's assert that we can do that by not having files_read_raw_ref() itself operate on *failure_errno in addition to passing it on. Instead we'll assert that if we return non-zero we actually do set errno, thus assuring ourselves and callers that they can trust the resulting "failure_errno". Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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committed by
Junio C Hamano

parent
8b72fea7e9
commit
df3458e957
8
refs.c
8
refs.c
@ -1648,7 +1648,8 @@ int for_each_fullref_in_prefixes(const char *namespace,
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static int refs_read_special_head(struct ref_store *ref_store,
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const char *refname, struct object_id *oid,
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struct strbuf *referent, unsigned int *type)
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struct strbuf *referent, unsigned int *type,
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int *failure_errno)
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{
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struct strbuf full_path = STRBUF_INIT;
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struct strbuf content = STRBUF_INIT;
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@ -1658,7 +1659,8 @@ static int refs_read_special_head(struct ref_store *ref_store,
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if (strbuf_read_file(&content, full_path.buf, 0) < 0)
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goto done;
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result = parse_loose_ref_contents(content.buf, oid, referent, type);
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result = parse_loose_ref_contents(content.buf, oid, referent, type,
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failure_errno);
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done:
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strbuf_release(&full_path);
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@ -1673,7 +1675,7 @@ int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
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assert(failure_errno);
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if (!strcmp(refname, "FETCH_HEAD") || !strcmp(refname, "MERGE_HEAD")) {
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return refs_read_special_head(ref_store, refname, oid, referent,
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type);
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type, failure_errno);
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}
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return ref_store->be->read_raw_ref(ref_store, refname, oid, referent,
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