tog: ensure stdin is a tty This guards against {mis,ab}use such as `tog < /dev/null`. ok plus fix from op@

plug leak in the commit graph iterator We fail to release the memory for the nodes. To fix it however, we some consumer of the commit graph iterator need to be corrected: the returned pointer is safe to be used only up until the next iter_next call; save a copy it if it's needed afterwards too. ok stsp@

tog: remove gcc ternary if extension ok stsp@

Group options in accordance with style(9) patch by Josiah Frentsos

tog: add missing checks for NULL pointers in log view state ok jamsek

tog: don't block when processing log view 'G' key map As per stsp's TODO item, make tog respond to key presses while "loading..." history. Initial testing in src.git appears to work as intended. ok stsp@

tog: fix delayed tree index update If a child blame view has been opened, halfdelay() is reset to a 1 second refresh rate, so the index in the header lags behind subtree navigation as we set the index based on the selected tree entry, which isn't updated till that refresh cycle completes. Don't wait for the selected_entry to update; instead, compute the index from the first displayed entry and the currently selected line index. improved by and ok stsp@

tog: move all 'G' logic into log_move_cursor_down() Previously, we only handled 'G' in log_move_cursor_down() when all commits had not yet been loaded; move the case where all commits are already loaded into this routine too, and simplify by handling both cases the same. This change was prompted by Mikhail's observation of a redundant assignment in the previous 'G' handling in log_move_cursor_down(). ok stsp@

tog: fix log 'd' keymap when last commit is displayed When at the end of the log view such that the currently selected line is greater than nlines/2, add--don't assign--the page down value to the selected index so we don't jump up when the user expects tog to scroll down. While here, rework log page down logic for a smoother UX in horizontal split mode by moving the selection cursor down rather than scrolling when 'd' or 'f' is entered if the last commit is already on screen. ok stsp@

tog: drop regex for line types to colour the diff view ok stsp@

tog: keymaps to jump to next/prev file/hunk in the diff Add () and {} key maps to navigate to the previous and next file or hunk in the diff. This required changing Got's diff API to collect line type metadata in addition to the line offsets already produced as prompted by stsp. ok stsp@

tog: add n{G,g} key map to jump to line n like less(1) Available to all views; for example, 99g will navigate to line 99 in the file if in a blame view or the 99th commit if in a log view. Includes improvements suggested by naddy and stsp. ok naddy@

remove pointless repo_close with leaked error; found by florian with scan-build

fix two missing error checks in tog; found by florian with scan-build

tog: refactor key map -> new view initialisation Deduplicate view initialisation boilerplate and simplify new key map view requests with dispatch routine. Includes improvements suggested by stsp. ok stsp@