lib-renderline: avoid possible infinite loop.

If window is tiny and measurement doesn't work, we can get into infinite
loop, not drawing anything.
Guard against this by testing that lineheight is positive.

Signed-off-by: NeilBrown <neil@brown.name>

diff --git a/DOC/TODO.md b/DOC/TODO.md
index 08d0677b0324da590b0fae4283916c2fd21288c5..fd80c4e195dcc3ced0a2a8e1eb858ee9f708769f 100644 (file)
--- a/DOC/TODO.md
+++ b/DOC/TODO.md
@@ -28,7 +28,7 @@ Current priorities
 Bugs to be fixed
 ----------------
 
-- [ ] lib-renderline in a 1x1 pane spins.  Happens if I 'elc' while cursor
+- [X] lib-renderline in a 1x1 pane spins.  Happens if I 'elc' while cursor
       is in a search popup.
 - [X] notmuch compose adds 'Re:' if it already exists
 - [ ] x11selection doesn't work properly on second ncurses display
@@ -37,7 +37,7 @@ Bugs to be fixed
 - [X] introduce per-pane timestamp so code can easily tell if it has run too long
 - [ ] teach input to allow a repeat command to be registered so that e.g.
       search/replace and do a bit of work, then ask to be called again.
-      input can cancel this on suitable input.
+      input pboard_waican cancel this on suitable input.
 - [X] handle reply-to header when replying to emails
 - [X] file names created for attachments need spaces etc translated
       for scp to work well ... at least when ncurses wants to use scp.

diff --git a/lib-renderline.c b/lib-renderline.c
index 568ad431b2cfbf42e8cabd74f0a4a519da107317..6a7a43f683d15bad162ac5ed615c476e3f5dba23 100644 (file)
--- a/lib-renderline.c
+++ b/lib-renderline.c
@@ -524,6 +524,9 @@ DEF_CMD(renderline)
        update_line_height(p, focus, &line_height, &ascent, &twidth, &center,
                           line, scale);
 
+       if (line_height <= 0)
+               return Einval;
+
        if (!wrap)
                x -= shift_left;
        else