Add new user option table-latex-environment

* lisp/textmodes/table.el (table-latex-environment): New user
option (bug#55333).
(table--generate-source-prologue): Use it.

etc/NEWS

@@ -2135,6 +2135,12 @@ This holds the value of the previous call to 'set-locale-environment'.
 This macro can be used to change the locale temporarily while
 executing code.
 
+** table.el
+
+---
+*** New user option 'table-latex-environment'.
+This allows switching between "table" and "tabular".
+
 ** Tabulated List Mode
 
 +++

lisp/textmodes/table.el

@@ -753,6 +753,16 @@ the cell contents dynamically."
   :type 'string
   :group 'table)
 
+(defcustom table-latex-environment "tabular"
+  "Which tabular-compatible environment to use when generating latex.
+\"tabular\" and \"longtable\" are known to work."
+  :tag "Latex environment used to export tables"
+  :type '(choice
+	  (const :tag "tabular" "tabular")
+	  (const :tag "longtable"  "longtable")
+          string)
+  :version "29.1")
+
 (defcustom table-cals-thead-rows 1
   "Number of top rows to become header rows in CALS table."
   :tag "CALS Header Rows"
@@ -3025,7 +3035,8 @@ CALS (DocBook DTD):
 		"")))
      ((eq language 'latex)
       (insert (format "%% This LaTeX table template is generated by emacs %s\n" emacs-version)
-	      "\\begin{tabular}{|" (apply #'concat (make-list (length col-list) "l|")) "}\n"
+	      "\\begin{" table-latex-environment "}{|"
+              (apply #'concat (make-list (length col-list) "l|")) "}\n"
 	      "\\hline\n"))
      ((eq language 'cals)
       (insert (format "<!-- This CALS table template is generated by emacs %s -->\n" emacs-version)
@@ -3051,7 +3062,7 @@ CALS (DocBook DTD):
      ((eq language 'html)
       (insert "</table>\n"))
      ((eq language 'latex)
-      (insert "\\end{tabular}\n"))
+      (insert "\\end{" table-latex-environment "}\n"))
      ((eq language 'cals)
       (set-marker-insertion-type (table-get-source-info 'colspec-marker) t) ;; insert before
       (save-excursion