fix nimindexterm in rst2tex/doc2tex [backport] (#19106)

* fix nimindexterm (rst2tex/doc2tex) [backport]

* Add support for indexing in rst

(cherry picked from commit 997ccc5)

config/nimdoc.tex.cfg

@@ -55,6 +55,11 @@ doc.file = """
 %
 % Compile it by:   xelatex    (up to 3 times to get labels generated)
 %                  -------
+% For example:
+%   xelatex file.tex
+%   xelatex file.tex
+%   makeindex file
+%   xelatex file.tex
 %
 \documentclass[a4paper,11pt]{article}
 \usepackage[a4paper,xetex,left=3cm,right=3cm,top=1.5cm,bottom=2cm]{geometry}
@@ -97,7 +102,9 @@ doc.file = """
 \usepackage{parskip}  % paragraphs delimited by vertical space, no indent
 \usepackage{graphicx}
 
-\newcommand{\nimindexterm}[2]{#2\label{#1}}
+\usepackage{makeidx}
+\newcommand{\nimindexterm}[2]{#2\index{#2}\label{#1}}
+\makeindex
 
 \usepackage{dingbat} % for \carriagereturn, etc
 \usepackage{fvextra}  % for code blocks (works better than original fancyvrb)
@@ -241,5 +248,8 @@ doc.file = """
 \maketitle
 
 $content
+
+\printindex
+
 \end{document}
 """

lib/packages/docutils/rstgen.nim

@@ -406,7 +406,7 @@ proc renderIndexTerm*(d: PDoc, n: PRstNode, result: var string) =
   var term = ""
   renderAux(d, n, term)
   setIndexTerm(d, changeFileExt(extractFilename(d.filename), HtmlExt), id, term, d.currentSection)
-  dispA(d.target, result, "<span id=\"$1\">$2</span>", "\\nimindexterm{$2}{$1}",
+  dispA(d.target, result, "<span id=\"$1\">$2</span>", "\\nimindexterm{$1}{$2}",
         [id, term])
 
 type

tools/kochdocs.nim

@@ -298,6 +298,12 @@ proc nim2pdf(src: string, dst: string, nimArgs: string) =
     # `>` should work on windows, if not, we can use `execCmdEx`
     let cmd = "xelatex -interaction=nonstopmode -output-directory=$# $# > $#" % [outDir.quoteShell, texFile.quoteShell, xelatexLog.quoteShell]
     exec(cmd) # on error, user can inspect `xelatexLog`
+    if i == 1:  # build .ind file
+      var texFileBase = texFile
+      texFileBase.removeSuffix(".tex")
+      let cmd = "makeindex $# > $#" % [
+          texFileBase.quoteShell, xelatexLog.quoteShell]
+      exec(cmd)
   moveFile(texFile.changeFileExt("pdf"), dst)
 
 proc buildPdfDoc*(nimArgs, destPath: string) =