fix #16973 ; nim doc now shows correct, canonical import name in title (#16999)

* nim doc now shows correct import name in title

compiler/docgen.nim

@@ -63,7 +63,22 @@ proc prettyString(a: object): string =
   for k, v in fieldPairs(a):
     result.add k & ": " & $v & "\n"
 
-proc presentationPath*(conf: ConfigRef, file: AbsoluteFile, isTitle = false): RelativeFile =
+proc canonicalImport*(conf: ConfigRef, file: AbsoluteFile): string =
+  ##[
+  Shows the canonical module import, e.g.:
+  system, std/tables, fusion/pointers, system/assertions, std/private/asciitables
+  ]##
+  var ret = getRelativePathFromConfigPath(conf, file, isTitle = true)
+  let dir = getNimbleFile(conf, $file).parentDir.AbsoluteDir
+  if not dir.isEmpty:
+    let relPath = relativeTo(file, dir)
+    if not relPath.isEmpty and (ret.isEmpty or relPath.string.len < ret.string.len):
+      ret = relPath
+  if ret.isEmpty:
+    ret = relativeTo(file, conf.projectPath)
+  result = ret.string.nativeToUnixPath.changeFileExt("")
+
+proc presentationPath*(conf: ConfigRef, file: AbsoluteFile): RelativeFile =
   ## returns a relative file that will be appended to outDir
   let file2 = $file
   template bail() =
@@ -97,9 +112,6 @@ proc presentationPath*(conf: ConfigRef, file: AbsoluteFile, isTitle = false): Re
     bail()
   if isAbsolute(result.string):
     result = file.string.splitPath()[1].RelativeFile
-  if isTitle:
-    result = result.string.nativeToUnixPath.RelativeFile
-  else:
   result = result.string.replace("..", dotdotMangle).RelativeFile
   doAssert not result.isEmpty
   doAssert not isAbsolute(result.string)
@@ -1259,8 +1271,7 @@ proc genOutFile(d: PDoc, groupedToc = false): Rope =
     setIndexTerm(d[], external, "", title)
   else:
     # Modules get an automatic title for the HTML, but no entry in the index.
-    # better than `extractFilename(changeFileExt(d.filename, ""))` as it disambiguates dups
+    title = canonicalImport(d.conf, AbsoluteFile d.filename)
-    title = $presentationPath(d.conf, AbsoluteFile d.filename, isTitle = true).changeFileExt("")
   var subtitle = "".rope
   if d.meta[metaSubtitle] != "":
     dispA(d.conf, subtitle, "<h2 class=\"subtitle\">$1</h2>",

compiler/options.nim

@@ -761,8 +761,25 @@ when (NimMajor, NimMinor) < (1, 1) or not declared(isRelativeTo):
     let ret = relativePath(path, base)
     result = path.len > 0 and not ret.startsWith ".."
 
-proc getRelativePathFromConfigPath*(conf: ConfigRef; f: AbsoluteFile): RelativeFile =
+const stdlibDirs = [
+  "pure", "core", "arch",
+  "pure/collections",
+  "pure/concurrency",
+  "pure/unidecode", "impure",
+  "wrappers", "wrappers/linenoise",
+  "windows", "posix", "js"]
+
+const
+  pkgPrefix = "pkg/"
+  stdPrefix = "std/"
+
+proc getRelativePathFromConfigPath*(conf: ConfigRef; f: AbsoluteFile, isTitle = false): RelativeFile =
   let f = $f
+  if isTitle:
+    for dir in stdlibDirs:
+      let path = conf.libpath.string / dir / f.lastPathPart
+      if path.cmpPaths(f) == 0:
+        return RelativeFile(stdPrefix & f.splitFile.name)
   template search(paths) =
     for it in paths:
       let it = $it
@@ -784,18 +801,8 @@ proc findFile*(conf: ConfigRef; f: string; suppressStdlib = false): AbsoluteFile
           result = rawFindFile2(conf, RelativeFile f.toLowerAscii)
   patchModule(conf)
 
-const stdlibDirs = [
-  "pure", "core", "arch",
-  "pure/collections",
-  "pure/concurrency",
-  "pure/unidecode", "impure",
-  "wrappers", "wrappers/linenoise",
-  "windows", "posix", "js"]
-
 proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFile =
   # returns path to module
-  const pkgPrefix = "pkg/"
-  const stdPrefix = "std/"
   var m = addFileExt(modulename, NimExt)
   if m.startsWith(pkgPrefix):
     result = findFile(conf, m.substr(pkgPrefix.len), suppressStdlib = true)

nimdoc/test_out_index_dot_html/expected/index.html

@@ -17,7 +17,7 @@
 <link href='https://fonts.googleapis.com/css?family=Source+Code+Pro:400,500,600' rel='stylesheet' type='text/css'/>
 
 <!-- CSS -->
-<title>foo</title>
+<title>nimdoc/test_out_index_dot_html/foo</title>
 <link rel="stylesheet" type="text/css" href="nimdoc.out.css">
 
 <script type="text/javascript" src="dochack.js"></script>
@@ -64,7 +64,7 @@ window.addEventListener('DOMContentLoaded', main);
 <body>
 <div class="document" id="documentId">
   <div class="container">
-    <h1 class="title">foo</h1>
+    <h1 class="title">nimdoc/test_out_index_dot_html/foo</h1>
     <div class="row">
   <div class="three columns">
   <div class="theme-switch-wrapper">