Matthew John Cheetham via GitGitGadget wrote:
> diff --git a/git-compat-util.h b/git-compat-util.h
> index a76d0526f79..f11c44517d7 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -1266,6 +1266,28 @@ static inline int skip_iprefix(const char *str, const char *prefix,
> return 0;
> }
>
> +/*
> + * Like skip_prefix_mem, but compare case-insensitively. Note that the
> + * comparison is done via tolower(), so it is strictly ASCII (no multi-byte
> + * characters or locale-specific conversions).
> + */
> +static inline int skip_iprefix_mem(const char *buf, size_t len,
> + const char *prefix,
> + const char **out, size_t *outlen)
> +{
> + size_t prefix_len = strlen(prefix);
> + if (len < prefix_len)
> + return 0;
> +
> + if (!strncasecmp(buf, prefix, prefix_len)){
> + *out = buf + prefix_len;
> + *outlen = len - prefix_len;
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> static inline int strtoul_ui(char const *s, int base, unsigned int *result)
> {
> unsigned long ul;
> diff --git a/http.c b/http.c
> index 8a5ba3f4776..7a56a3db5f7 100644
> --- a/http.c
> +++ b/http.c
> @@ -183,6 +183,124 @@ size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
> return nmemb;
> }
>
> +/*
> + * A folded header continuation line starts with at least one single whitespace
> + * character. It is not a continuation line if the line is *just* a newline.
> + * The RFC for HTTP states that CRLF is the header field line ending, but some
> + * servers may use LF only; we accept both.
> + */
> +static inline int is_hdr_continuation(const char *ptr, const size_t size)
> +{
> + /* totally empty line or normal header */
> + if (!size || !isspace(*ptr))
> + return 0;
> +
> + /* empty line with LF line ending */
> + if (size == 1 && ptr[0] == '\n')
> + return 0;
> +
> + /* empty line with CRLF line ending */
> + if (size == 2 && ptr[0] == '\r' && ptr[1] == '\n')
> + return 0;
> +
> + return 1;
> +}
> +
> +static size_t fwrite_wwwauth(char *ptr, size_t eltsize, size_t nmemb, void *p)
> +{
> + size_t size = eltsize * nmemb;
> + struct strvec *values = &http_auth.wwwauth_headers;
> + struct strbuf buf = STRBUF_INIT;
> + const char *val;
> + size_t val_len;
> +
> + /*
> + * Header lines may not come NULL-terminated from libcurl so we must
> + * limit all scans to the maximum length of the header line, or leverage
> + * strbufs for all operations.
> + *
> + * In addition, it is possible that header values can be split over
> + * multiple lines as per RFC 2616 (even though this has since been
> + * deprecated in RFC 7230). A continuation header field value is
> + * identified as starting with a space or horizontal tab.
> + *
> + * The formal definition of a header field as given in RFC 2616 is:
> + *
> + * message-header = field-name ":" [ field-value ]
> + * field-name = token
> + * field-value = *( field-content | LWS )
> + * field-content = <the OCTETs making up the field-value
> + * and consisting of either *TEXT or combinations
> + * of token, separators, and quoted-string>
> + */
> +
> + /* Start of a new WWW-Authenticate header */
> + if (skip_iprefix_mem(ptr, size, "www-authenticate:", &val, &val_len)) {
> + strbuf_add(&buf, val, val_len);
> +
> + /*
> + * Strip the CRLF that should be present at the end of each
> + * field as well as any trailing or leading whitespace from the
> + * value.
> + */
> + strbuf_trim(&buf);
> +
> + strvec_push(values, buf.buf);
> + http_auth.header_is_last_match = 1;
> + goto exit;
> + }
> +
> + /*
> + * This line could be a continuation of the previously matched header
> + * field. If this is the case then we should append this value to the
> + * end of the previously consumed value.
> + */
> + if (http_auth.header_is_last_match && is_hdr_continuation(ptr, size)) {
> + /*
> + * Trim the CRLF and any leading or trailing from this line.
> + */
> + strbuf_add(&buf, ptr, size);
> + strbuf_trim(&buf);
> +
> + /*
> + * At this point we should always have at least one existing
> + * value, even if it is empty. Do not bother appending the new
> + * value if this continuation header is itself empty.
> + */
> + if (!values->nr) {
> + BUG("should have at least one existing header value");
> + } else if (buf.len) {
> + char *prev = xstrdup(values->v[values->nr - 1]);
> +
> + /* Join two non-empty values with a single space. */
> + const char *const sp = *prev ? " " : "";
> +
> + strvec_pop(values);
> + strvec_pushf(values, "%s%s%s", prev, sp, buf.buf);
> + free(prev);
> + }
> +
> + goto exit;
> + }
> +
> + /* This is the start of a new header we don't care about */
> + http_auth.header_is_last_match = 0;
> +
> + /*
> + * If this is a HTTP status line and not a header field, this signals
> + * a different HTTP response. libcurl writes all the output of all
> + * response headers of all responses, including redirects.
> + * We only care about the last HTTP request response's headers so clear
> + * the existing array.
> + */
> + if (!strncasecmp(ptr, "http/", 5))
> + strvec_clear(values);
I found this updated version of 'fwrite_wwwauth()' (using
'skip_iprefix_mem()', 'is_hdr_continuation()', and 'strncasecmp()') a bit
easier to read than previous iterations - possibly because all the
prefix-skipping is done before adding to 'buf', so 'buf' represents *only*
the line's header value (possibly with leading/trailing whitespace, which is
trimmed). Plus, avoiding unnecessary allocations is always nice.
> +
> +exit:
> + strbuf_release(&buf);
> + return size;
> +}
