Don't wrap punctuation after LaTeX

If punctuation follows a latex expression, consider the punctuation as part of the expression to avoid it being wrapped on to the next line.

This doesn't address the root cause of why this bug appeared, but it works as a quick fix.

Author: axlewin

src/app/components/elements/markup/latexRendering.ts

@@ -252,7 +252,14 @@ export function katexify(html: string, user: Immutable<PotentialUser> | null, bo
                 endMatch(match, search);
             }
             if (search.matched && match) {
-                const latex = html.substring(index + (search.olen || 0), match.index + match[0].length - (search.clen || 0));
+                let latex = html.substring(index + (search.olen || 0), match.index + match[0].length - (search.clen || 0));
+
+                const charAfter = html[match.index + match[0].length];
+                if (/[.,"':;?!)]/.test(charAfter)) {
+                    latex += charAfter;
+                    match.index++;
+                }
+
                 const latexUnEntitied = he.decode(latex);
                 const latexMunged = munge(latexUnEntitied);
                 let macrosToUse;