jiebi/CodeConvo huggingface dataset:
6.5.2. <ins> The "Trailer" header field (field.trailer) can be sent to indicate fields likely to be sent in the trailer section, which allows recipients to prepare for their receipt before processing the content.  For example, this could be useful if a field name indicates that a dynamic checksum should be calculated as the content is received and then immediately checked upon receipt of the trailer field value. </ins> Like header fields, trailer fields with the same name are processed in the order received; multiple trailer field lines with the same name have the equivalent semantics as appending the multiple values <del> as a list of members, even when the field lines are received in separate trailer sections.  Trailer fields that might be generated more than once during a message MUST be defined as a list-based field even if each member value is only processed once per field line received. Trailer fields are expected (but not required) to be processed one trailer section at a time.  That is, for each trailer section received, a recipient that is looking for trailer fields will parse the received section into fields, invoke any associated processing for those fields at that point in the message processing, and then append those fields to the set of trailer fields received for the overall message. This behavior allows for iterative processing of trailer fields that contain incremental signatures or mid-stream status information, and fields that might refer to each other's values within the same section.  However, there is no guarantee that trailer sections won't shift in relation to the content stream, or won't be recombined (or dropped) in transit.  Trailer fields that refer to data outside the present trailer section need to use self-descriptive references (i.e., refer to the data by name, ordinal position, or an octet range) rather than assume it is the data most recently received. Likewise, at the end of a message, a recipient MAY treat the entire set of received trailer fields as one data structure to be considered as the message concludes.  Additional processing expectations, if any, can be defined within the field specification for a field intended for use in trailers. </del> <ins> as a list of members.  Trailer fields that might be generated more than once during a message MUST be defined as a list-based field even if each member value is only processed once per field line received. At the end of a message, a recipient MAY treat the set of received trailer fields as a data structure of key/value pairs, similar to (but separate from) the header fields.  Additional processing expectations, if any, can be defined within the field specification for a field intended for use in trailers. </ins> 7.
determined by looking at the message itself, after decoding or reconstituting parts that have been compressed or elided in transit, without requiring an understanding of the sender's current <del> application state (established via prior messages). </del> <ins> application state (established via prior messages).  However, a client MUST retain knowledge of the request when parsing, interpreting, or caching a corresponding response.  For example, responses to the method look just like the beginning of a response to , but cannot be parsed in the same manner. </ins> Note that this message abstraction is a generalization across many versions of HTTP, including features that might not be found in some
(a.k.a., <del> ), selection of the best response representation (regardless of the status code) is performed by the user agent after receiving an initial response from the origin server that contains a list of resources for alternative representations. If the user agent is not satisfied by the initial response representation, it can perform a GET request on one or more of the alternative resources, selected based on metadata included in the list, to obtain a different form of representation for that response. Selection of alternatives might be performed automatically by the user agent or manually by the user selecting from a generated (possibly hypertext) menu. Note that the above refers to representations of the response, in general, not representations of the resource.  The alternative representations are only considered representations of the target resource if the response in which those alternatives are provided has the semantics of being a representation of the target resource (e.g., a response to a GET request) or has the semantics of providing links to alternative representations for the target resource (e.g., a </del> <ins> ), selection of content (regardless of the status code) is performed by the user agent after receiving an initial response.  The mechanism for reactive negotiation might be as simple as a list of references to alternative representations. </ins> <del> response to a GET request). </del> <ins> If the user agent is not satisfied by the initial response content, it can perform a GET request on one or more of the alternative resources to obtain a different representation.  Selection of such alternatives might be performed automatically (by the user agent) or manually (e.g., by the user selecting from a hypertext menu). </ins> A server might choose not to send an initial representation, other than the list of alternatives, and thereby indicate that reactive
(a.k.a., <del> ), selection of the best response representation (regardless of the status code) is performed by the user agent after receiving an initial response from the origin server that contains a list of resources for alternative representations. If the user agent is not satisfied by the initial response representation, it can perform a GET request on one or more of the alternative resources, selected based on metadata included in the list, to obtain a different form of representation for that response. Selection of alternatives might be performed automatically by the user agent or manually by the user selecting from a generated (possibly hypertext) menu. Note that the above refers to representations of the response, in general, not representations of the resource.  The alternative representations are only considered representations of the target resource if the response in which those alternatives are provided has the semantics of being a representation of the target resource (e.g., a response to a GET request) or has the semantics of providing links to alternative representations for the target resource (e.g., a response to a GET request). </del> <ins> ), selection of content (regardless of the status code) is performed by the user agent after receiving an initial response.  The mechanism for reactive negotiation might be as simple as a list of references to alternative representations. If the user agent is not satisfied by the initial response content, it can perform a GET request on one or more of the alternative resources to obtain a different representation.  Selection of such alternatives might be performed automatically (by the user agent) or manually (e.g., by the user selecting from a hypertext menu). </ins> A server might choose not to send an initial representation, other than the list of alternatives, and thereby indicate that reactive
robustness (see request.smuggling). HTTP does not place a predefined limit on the length of a request- <del> line, as described in Semantics-conformance.  A server that receives a method longer than any that it implements SHOULD respond with a </del> <ins> line, as described in Semantics.  A server that receives a method longer than any that it implements SHOULD respond with a </ins> status code.  A server that receives a request-target longer than any URI it wishes to parse MUST respond with a
The <del> of request-target is only used for CONNECT requests (CONNECT). </del> <ins> of request-target is only used for CONNECT requests (CONNECT).  It consists of only the and number of the tunnel destination, separated by a colon (":"). </ins> When making a CONNECT request to establish a tunnel through one or <del> more proxies, a client MUST send only the target URI's authority component (excluding any userinfo and its "@" delimiter) as the request-target.  For example, </del> <ins> more proxies, a client MUST send only the host and port of the tunnel destination as the request-target.  The client obtains the host and port from the target URI's component, except that the scheme's default port is sent if the target URI elides the port.  For example, a CONNECT request to "http://www.example.com" looks like </ins> 3.2.4.
3.3. <del> Since the request-target often contains only part of the user agent's target URI, a server constructs its value to properly service the request (target.resource). </del> <ins> The target URI is the </ins> <del> If the </del> <ins> when the request-target is in </ins> <del> is in </del> <ins> . In that case, a server will parse the URI into its generic components for further evaluation. </ins> <del> , the target URI is the same as the request-target.  Otherwise, the target URI is constructed as follows: </del> <ins> Otherwise, the server reconstructs the target URI from the connection context and various parts of the request message in order to identify the target resource (target.resource): </ins> <del> Example 1: the following message received over an insecure TCP connection </del> <ins> Example 1: the following message received over a secure connection </ins> has a target URI of <del> Example 2: the following message received over a secured connection </del> <ins> Example 2: the following message received over an insecure connection </ins> has a target URI of <del> Recipients of an HTTP/1.0 request that lacks a header field might need to use heuristics (e.g., examination of the URI path for something unique to a particular host) in order to guess the target URI's authority component. </del> <ins> If the target URI's authority component is empty and its URI scheme requires a non-empty authority (as is the case for "http" and "https"), the server can reject the request or determine whether a configured default applies that is consistent with the incoming connection's context.  Context might include connection details like address and port, what security has been applied, and locally-defined information specific to that server's configuration.  An empty authority is replaced with the configured default before further processing of the request. Supplying a default name for authority within the context of a secured connection is inherently unsafe if there is any chance that the user agent's intended authority might differ from the selected default.  A server that can uniquely identify an authority from the request context MAY use that identity as a default without this risk. Alternatively, it might be better to redirect the request to a safe resource that explains how to obtain a new client. Note that reconstructing the client's target URI is only half of the process for identifying a target resource.  The other half is determining whether that target URI identifies a resource for which the server is willing and able to send a response, as defined in routing.reject. </ins> 4.
When a message does not have a <del> header field, a Content-Length header field can provide the anticipated size, as a decimal number of octets, for potential content.  For messages that do include content, the Content-Length field value provides the framing information necessary for determining where the data (and message) ends.  For messages that do not include content, the Content-Length indicates the size of the </del> <ins> header field, a Content-Length header field (field.content-length) can provide the anticipated size, as a decimal number of octets, for potential content.  For messages that do include content, the Content-Length field value provides the framing information necessary for determining where the data (and message) ends.  For messages that do not include content, the Content-Length indicates the size of the </ins> selected representation (field.content-length). A sender MUST NOT send a Content-Length header field in any message
Transfer-Encoding header fields received in a successful response to CONNECT. <del> Content within a CONNECT request message has no defined semantics; sending content in a CONNECT request might cause some existing implementations to reject the request. </del> <ins> A CONNECT request message does not have content.  The interpretation of and allowability of data sent after the header section of the CONNECT request message is specific to the version of HTTP in use. </ins> Responses to the CONNECT method are not cacheable.
4.2.3. <del> Since the "http" and "https" schemes conform to the URI generic syntax, such URIs are normalized and compared according to the algorithm defined in RFC3986, using the defaults described above for each scheme. If the port is equal to the default port for a scheme, the normal form is to omit the port subcomponent.  When not being used as the target of an OPTIONS request, an empty path component is equivalent to an absolute path of "/", so the normal form is to provide a path of "/" instead.  The scheme and host are case-insensitive and normally provided in lowercase; all other components are compared in a case-sensitive manner.  Characters other than those in the "reserved" set are equivalent to their percent-encoded octets: the normal form is to not encode them (see Sections RFC3986 and RFC3986 of RFC3986). </del> <ins> The "http" and "https" URI are normalized and compared according to the methods defined in RFC3986, using the defaults described above for each scheme. HTTP does not require use of a specific method for determining equivalence.  For example, a cache key might be compared as a simple string, after syntax-based normalization, or after scheme-based normalization. Two HTTP URIs that are equivalent after normalization (using any method) can be assumed to identify the same resource, and any HTTP component MAY perform normalization.  As a result, distinct resources SHOULD NOT be identified by HTTP URIs that are equivalent after normalization (using any method defined in RFC3986). Scheme-based normalization (RFC3986) of "http" and "https" URIs involves the following additional rules: </ins> For example, the following three URIs are equivalent:
HTTP/1.1 defaults to the use of , allowing multiple requests and responses to be carried over a <del> single connection.  The " " connection option is used to signal that a connection will not persist after the current request/response.  HTTP implementations SHOULD support persistent connections. </del> <ins> single connection.  HTTP implementations SHOULD support persistent connections. </ins> A recipient determines whether a connection is persistent or not based on the most recently received message's protocol version and
A client that does not support <del> MUST send the "close" connection option in every request message. </del> <ins> MUST send the connection option in every request message. </ins> A server that does not support <del> MUST send the "close" connection option in every response message that does not have a </del> <ins> MUST send the connection option in every response message that does not have a </ins> status code. A client MAY send additional requests on a persistent connection <del> until it sends or receives a " </del> <ins> until it sends or receives a </ins> <del> " connection option or receives an HTTP/1.0 response without a "keep- </del> <ins> connection option or receives an HTTP/1.0 response without a "keep- </ins> alive" connection option. In order to remain persistent, all messages on a connection need to
directive (defined by RFC8246) instructs caches to forgo revalidation of fresh responses even when requested by the client. <del> Conditional request header fields that are defined by extensions to HTTP might place conditions on all recipients, on the state of the target resource in general, or on a group of resources.  For instance, the "If" header field in WebDAV can make a request conditional on various aspects of multiple resources, such as locks, if the recipient understands and implements that field (RFC4918). </del> Although conditional request header fields are defined as being usable with the HEAD method (to keep HEAD's semantics consistent with those of GET), there is no point in sending a conditional HEAD
changes that were partially applied, and then automatically retrying the requests that failed. <del> Some clients use weaker signals to initiate automatic retries.  For example, when a POST request is sent, but the underlying transport connection is closed before any part of the response is received. Although this is commonly implemented, it is not recommended. </del> <ins> Some clients take a riskier approach and attempt to guess when an automatic retry is possible.  For example, a client might automatically retry a POST request if the underlying transport connection closed before any part of a response is received, particularly if an idle persistent connection was used. </ins> A proxy MUST NOT automatically retry non-idempotent requests.  A client SHOULD NOT automatically retry a failed automatic retry.
protocol elements, extensibility mechanisms, and the "http" and "https" Uniform Resource Identifier (URI) schemes. <del> This document obsoletes RFC 2818, RFC 7231, RFC 7232, RFC 7233, RFC 7235, RFC 7538, RFC 7615, RFC 7694, and portions of RFC 7230. </del> <ins> This document updates RFC 3864 and obsoletes RFC 2818, RFC 7231, RFC 7232, RFC 7233, RFC 7235, RFC 7538, RFC 7615, RFC 7694, and portions of RFC 7230. </ins> Editorial Note
and discarding the content for a HEAD request, since HEAD is usually requested for the sake of efficiency. <del> A content within a HEAD request message has no defined semantics; sending content in a HEAD request might cause some existing implementations to reject the request. </del> <ins> A client SHOULD NOT generate content in a HEAD request.  Content received in a HEAD request has no defined semantics, cannot alter the meaning or target of the request, and might lead some implementations to reject the request and close the connection because of its potential as a request smuggling attack (request.smuggling). </ins> The response to a HEAD request is cacheable; a cache MAY use it to satisfy subsequent HEAD requests unless otherwise indicated by the
that have the same field name into one field line, without changing the semantics of the message, by appending each subsequent field line value to the initial field line value in order, separated by a comma <del> and </del> <ins> (",") and optional whitespace ( </ins> <del> (optional whitespace).  For consistency, use comma SP. </del> <ins> , defined in whitespace).  For consistency, use comma SP. </ins> The order in which field lines with the same name are received is therefore significant to the interpretation of the field value; a
A construct "#" is defined, similar to "*", for defining comma- delimited lists of elements.  The full form is "<n>#<m>element" indicating at least <n> and at most <m> elements, each separated by a <del> single comma (",") and optional whitespace (OWS). </del> <ins> single comma (",") and optional whitespace ( , defined in whitespace). </ins> 5.6.1.1.
responses) can be sent at any time after a request is received, even if the request is not yet complete.  A response can complete before <del> its corresponding request is complete.  Likewise, clients are not expected to wait any specific amount of time for a response.  Clients (including intermediaries) might abandon a request if the response is not forthcoming within a reasonable period of time. </del> <ins> its corresponding request is complete (message.framing).  Likewise, clients are not expected to wait any specific amount of time for a response.  Clients (including intermediaries) might abandon a request if the response is not forthcoming within a reasonable period of time. </ins> A client that receives a response while it is still sending the associated request SHOULD continue sending that request, unless it
for the <del> . </del> <ins> .  A successful response reflects the quality of "sameness" identified by the target URI (RFC3986).  Hence, retrieving identifiable information via HTTP is usually performed by making a GET request on an identifier associated with the potential for providing that information in a response. </ins> GET is the primary mechanism of information retrieval and the focus <del> of almost all performance optimizations.  Hence, when people speak of retrieving some identifiable information via HTTP, they are generally referring to making a GET request.  A successful response reflects the quality of "sameness" identified by the target URI.  In turn, constructing applications such that they produce a URI for each important resource results in more resources being available for other applications, producing a network effect that promotes further expansion of the Web. </del> <ins> of almost all performance optimizations.  Applications that produce a URI for each important resource can benefit from those optimizations while enabling their reuse by other applications, creating a network effect that promotes further expansion of the Web. </ins> It is tempting to think of resource identifiers as remote file system pathnames and of representations as being a copy of the contents of
information. Other prefixes are sometimes used in HTTP field names; for example, <del> "Accept-" is used in many content negotiation headers.  These prefixes are only an aid to recognizing the purpose of a field, and do not trigger automatic processing. </del> <ins> "Accept-" is used in many content negotiation headers, and "Content-" is used as explained in content.  These prefixes are only an aid to recognizing the purpose of a field, and do not trigger automatic processing. </ins> 16.3.2.2.
message.  However, if the real host is considered to be sensitive information, a sender MAY replace it with a pseudonym.  If a port is not provided, a recipient MAY interpret that as meaning it was <del> received on the default TCP port, if any, for the received-protocol. </del> <ins> received on the default port, if any, for the received-protocol. </ins> A sender MAY generate comments to identify the software of each recipient, analogous to the
Browser fingerprinting is a set of techniques for identifying a specific user agent over time through its unique set of characteristics.  These characteristics might include information <del> related to its TCP behavior, feature capabilities, and scripting environment, though of particular interest here is the set of unique characteristics that might be communicated via HTTP.  Fingerprinting is considered a privacy concern because it enables tracking of a user agent's behavior over time (Bujlow) without the corresponding controls that the user might have over other forms of data collection (e.g., cookies).  Many general-purpose user agents (i.e., Web browsers) have taken steps to reduce their fingerprints. </del> <ins> related to how it uses the underlying transport protocol, feature capabilities, and scripting environment, though of particular interest here is the set of unique characteristics that might be communicated via HTTP.  Fingerprinting is considered a privacy concern because it enables tracking of a user agent's behavior over time (Bujlow) without the corresponding controls that the user might have over other forms of data collection (e.g., cookies).  Many general-purpose user agents (i.e., Web browsers) have taken steps to reduce their fingerprints. </ins> There are a number of request header fields that might reveal information to servers that is sufficiently unique to enable