clean up error conventions of remote.c:match_explicit

match_explicit is called for each push refspec to try to fully resolve the source and destination sides of the refspec. Currently, we look at each refspec and report errors on both the source and the dest side before aborting. It makes sense to report errors for each refspec, since an error in one is independent of an error in the other. However, reporting errors on the 'dst' side of a refspec if there has been an error on the 'src' side does not necessarily make sense, since the interpretation of the 'dst' side depends on the 'src' side (for example, when creating a new unqualified remote ref, we use the same type as the src ref). This patch lets match_explicit return early when the src side of the refspec is bogus. We still look at all of the refspecs before aborting the push, though. At the same time, we clean up the call signature, which previously took an extra "errs" flag. This was pointless, as we didn't act on that flag, but rather just passed it back to the caller. Instead, we now use the more traditional "return -1" to signal an error, and the caller aggregates the error count. This change fixes two bugs, as well: - the early return avoids a segfault when passing a NULL matched_src to guess_ref() - the check for multiple sources pointing to a single dest aborted if the "err" flag was set. Presumably the intent was not to bother with the check if we had no matched_src. However, since the err flag was passed in from the caller, we might abort the check just because a previous refspec had a problem, which doesn't make sense. In practice, this didn't matter, since due to the error flag we end up aborting the push anyway. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>