Differential D21509 Diff 51195 src/xsprintf/gitsprintf.php

Changeset View

Standalone View

src/xsprintf/gitsprintf.php

This file was added.

				<?php

				/**
				* Format a Git ref selector. This formatting is important when executing
				* commands like "git log" which can not unambiguously parse all values as
				* ref selectors.
				*
				* Supports the following conversions:
				*
				* %s Ref Selector
				* Escapes a Git ref selector. In particular, this will reject ref selectors
				* which Git may interpret as flags.
				*
				* %R Raw String
				* Passes text through unescaped.
				*/
				function gitsprintf($pattern /* , ... */) {
				$args = func_get_args();
				return xsprintf('xsprintf_git', null, $args);
				}

				/**
				* @{function:xsprintf} callback for Git encoding.
				*/
				function xsprintf_git($userdata, &$pattern, &$pos, &$value, &$length) {
				$type = $pattern[$pos];

				switch ($type) {
				case 's':

				// See T13589. Some Git commands accept both a ref selector and a list of
				// paths. For example:

				// $ git log <ref> -- <path> <path> ...

				// These commands disambiguate ref selectors from paths using "--", but
				// have no mechanism for disambiguating ref selectors from flags.

				// Thus, there appears to be no way (in the general case) to safely
				// invoke these commands with an arbitrary ref selector string: ref
				// selector strings like "--flag" may be interpreted as flags, not as
				// ref selectors.

				// To resolve this, we reject any ref selector which begins with "-".
				// These selectors are never valid anyway, so there is no loss of overall
				// correctness. It would be more desirable to pass them to Git in a way
				// that guarantees Git inteprets the string as a ref selector, but it
				// appears that no mechanism exists to allow this.

				if (preg_match('(^-)', $value)) {
				throw new Exception(
				pht(
				'Git ref selector "%s" is not a valid selector and can not be '.
				'passed to the Git CLI safely in the general case.',
				$value));
				}
				break;
				case 'R':
				$type = 's';
				break;
				}

				$pattern[$pos] = $type;
				}