Path: csiph.com!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail From: Dave Newsgroups: gnu.groff.bug Subject: [bug #57448] groff will not break a line at a hard hyphen following some letter combinations Date: Fri, 20 Dec 2019 05:36:27 -0500 (EST) Lines: 45 Approved: bug-groff@gnu.org Message-ID: References: <20191219-071637.sv93119.83466@savannah.gnu.org> <20191219-231340.sv93188.76941@savannah.gnu.org> <20191219-220856.sv93119.28405@savannah.gnu.org> <20191220-043627.sv93119.51933@savannah.gnu.org> NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: text/plain;charset=UTF-8 X-Trace: usenet.stanford.edu 1576838194 764 209.51.188.17 (20 Dec 2019 10:36:34 GMT) X-Complaints-To: action@cs.stanford.edu To: Dave , Bjarni Ingi Gislason , bug-groff@gnu.org Envelope-to: bug-groff@gnu.org X-PHP-Originating-Script: 1001:sendmail.php X-Savane-Server: savannah.gnu.org:443 [2001:470:142:5::79] X-Savane-Project: groff X-Savane-Tracker: bugs X-Savane-Item-ID: 57448 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Firefox/45.0 X-Apparently-From: 2605:a601:aac3:e300:55b7:e0e9:96ca:b482 (Savane authenticated user barx) In-Reply-To: <20191219-220856.sv93119.28405@savannah.gnu.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.79 X-BeenThere: bug-groff@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Bug reports for the GNU version of nroff, troff et al" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: <20191220-043627.sv93119.51933@savannah.gnu.org> X-Mailman-Original-References: <20191219-071637.sv93119.83466@savannah.gnu.org> <20191219-231340.sv93188.76941@savannah.gnu.org> <20191219-220856.sv93119.28405@savannah.gnu.org> Xref: csiph.com gnu.groff.bug:1581 Follow-up Comment #3, bug #57448 (project groff): But you are correct that kerning appears to be what triggers the bug. In the default font (TR), only four uppercase letters have kerning between them and a following hyphen: $ sed -n '/^kernpairs/,/^$/p' /usr/share/groff/current/font/devps/TR | grep '^[[:upper:]] - ' T - -92 V - -100 W - -65 Y - -111 (Side note: these four letters' glyphs are basically symmetrical, so it's unclear why this file lacks the same four combinations in reverse order; there are no kern pairs beginning with a hyphen.) Now look at all kern pairs beginning with any uppercase letter and ending with one of the above four: $ sed -n '/^kernpairs/,/^$/p' /usr/share/groff/current/font/devps/TR | grep '^[[:upper:]] [TVWY]' This generates my list of the 19 offending combinations. Thus a more succinct bug description would be: groff fails to break a line at a hyphen following two uppercase letters when the font file specifies kerning both between those letters and between the second letter and the hyphen. Curiously, the place where the line break should occur is never kerned: the break should always be after the hyphen, and no kern pairs have a hyphen as the first element. It is kerning that occurs before (what should be) a breakpoint that somehow inhibits breaking at that point. _______________________________________________________ Reply to this item at: _______________________________________________ Message sent via Savannah https://savannah.gnu.org/