Add \nobreak inside \sphinxAtStartPar

Else, a non-hyphenatable long word as first word in a narrow column in a
longtable/tabular (with column type e.g. p{1cm} from tabularcolumns
directive) gets shifted downwards vertically in PDF output.

Memo:

1. I did not find other cases where such a vertical shift may occur (I
tried with deeply nested lists and artificial words such as 'A'*32) with
LaTeX mark-up produced by Sphinx,

2. but with the support of hlist directive via PR #8779 using multicols
environment, there is again this situation of downwards shift of
non-hyphenatable long first words.  But it occurs whether or not
\sphinxAtStartPar is used (\nobreak does not modify this).

1 files changed, 1 insertions, 1 deletions

diff --git a/sphinx/texinputs/sphinx.sty b/sphinx/texinputs/sphinx.sty
index 33d3cc445..f040fde7f 100644
--- a/sphinx/texinputs/sphinx.sty
+++ b/sphinx/texinputs/sphinx.sty
@@ -412,7 +412,7 @@
 \DisableKeyvalOption{sphinx}{mathnumfig}
 % To allow hyphenation of first word in narrow contexts; no option,
 % customization to be done via 'preamble' key
-\newcommand*\sphinxAtStartPar{\hskip\z@skip}
+\newcommand*\sphinxAtStartPar{\nobreak\hskip\z@skip}
 % No need for the \hspace{0pt} trick (\hskip\z@skip) with luatex
 \ifdefined\directlua\let\sphinxAtStartPar\@empty\fi
 % user interface: options can be changed midway in a document!