tpl/tplimpl: Rework template management to get rid of concurrency issues

This more or less completes the simplification of the template handling code in Hugo started in v0.62.

The main motivation was to fix a long lasting issue about a crash in HTML content files  without front matter.

But this commit also comes with a big functional improvement.

As we now have moved the base template evaluation to the build stage we now use the same lookup rules for `baseof` as for `list` etc. type of templates.

This means that in this simple example you can have a `baseof` template for the `blog` section without having to duplicate the others:

```
layouts
├── _default
│   ├── baseof.html
│   ├── list.html
│   └── single.html
└── blog
    └── baseof.html
```

Also, when simplifying code, you often get rid of some double work, as shown in the "site building" benchmarks below.

These benchmarks looks suspiciously good, but I have repeated the below with ca. the same result. Compared to master:

```
name                              old time/op    new time/op    delta
SiteNew/Bundle_with_image-16        13.1ms ± 1%    10.5ms ± 1%  -19.34%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16    13.0ms ± 0%    10.7ms ± 1%  -18.05%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories-16      46.4ms ± 2%    43.1ms ± 1%   -7.15%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16            52.2ms ± 2%    47.8ms ± 1%   -8.30%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree-16        77.9ms ± 1%    70.9ms ± 1%   -9.01%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates-16      43.0ms ± 0%    37.2ms ± 1%  -13.54%  (p=0.029 n=4+4)
SiteNew/Page_collections-16         58.2ms ± 1%    52.4ms ± 1%   -9.95%  (p=0.029 n=4+4)

name                              old alloc/op   new alloc/op   delta
SiteNew/Bundle_with_image-16        3.81MB ± 0%    2.22MB ± 0%  -41.70%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16    3.60MB ± 0%    2.01MB ± 0%  -44.20%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories-16      19.3MB ± 1%    14.1MB ± 0%  -26.91%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16            70.7MB ± 0%    69.0MB ± 0%   -2.40%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree-16        37.1MB ± 0%    31.2MB ± 0%  -15.94%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates-16      17.6MB ± 0%    10.6MB ± 0%  -39.92%  (p=0.029 n=4+4)
SiteNew/Page_collections-16         25.9MB ± 0%    21.2MB ± 0%  -17.99%  (p=0.029 n=4+4)

name                              old allocs/op  new allocs/op  delta
SiteNew/Bundle_with_image-16         52.3k ± 0%     26.1k ± 0%  -50.18%  (p=0.029 n=4+4)
SiteNew/Bundle_with_JSON_file-16     52.3k ± 0%     26.1k ± 0%  -50.16%  (p=0.029 n=4+4)
SiteNew/Tags_and_categories-16        336k ± 1%      269k ± 0%  -19.90%  (p=0.029 n=4+4)
SiteNew/Canonify_URLs-16              422k ± 0%      395k ± 0%   -6.43%  (p=0.029 n=4+4)
SiteNew/Deep_content_tree-16          401k ± 0%      313k ± 0%  -21.79%  (p=0.029 n=4+4)
SiteNew/Many_HTML_templates-16        247k ± 0%      143k ± 0%  -42.17%  (p=0.029 n=4+4)
SiteNew/Page_collections-16           282k ± 0%      207k ± 0%  -26.55%  (p=0.029 n=4+4)
```

Fixes #6716
Fixes #6760
Fixes #6768
Fixes #6778

1 files changed, 0 insertions, 13 deletions

diff --git a/hugolib/page_test.go b/hugolib/page_test.go
index 9bcfc1fc8..d7cbc0fca 100644
--- a/hugolib/page_test.go
+++ b/hugolib/page_test.go
@@ -333,12 +333,6 @@ func checkPageSummary(t *testing.T, page page.Page, summary string, msg ...inter
 	}
 }
 
-func checkPageType(t *testing.T, page page.Page, pageType string) {
-	if page.Type() != pageType {
-		t.Fatalf("Page type is: %s.  Expected: %s", page.Type(), pageType)
-	}
-}
-
 func checkPageDate(t *testing.T, page page.Page, time time.Time) {
 	if page.Date() != time {
 		t.Fatalf("Page date is: %s.  Expected: %s", page.Date(), time)
@@ -542,7 +536,6 @@ func TestCreateNewPage(t *testing.T) {
 		checkPageTitle(t, p, "Simple")
 		checkPageContent(t, p, normalizeExpected(ext, "<p>Simple Page</p>\n"))
 		checkPageSummary(t, p, "Simple Page")
-		checkPageType(t, p, "page")
 	}
 
 	settings := map[string]interface{}{
@@ -562,7 +555,6 @@ func TestPageSummary(t *testing.T) {
 			checkPageContent(t, p, normalizeExpected(ext, "<p><a href=\"https://lipsum.com/\">Lorem ipsum</a> dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>\n\n<p>Additional text.</p>\n\n<p>Further text.</p>\n"), ext)
 			checkPageSummary(t, p, normalizeExpected(ext, "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Additional text."), ext)
 		}
-		checkPageType(t, p, "page")
 	}
 
 	testAllMarkdownEnginesForPages(t, assertFunc, nil, simplePageWithoutSummaryDelimiter)
@@ -575,7 +567,6 @@ func TestPageWithDelimiter(t *testing.T) {
 		checkPageTitle(t, p, "Simple")
 		checkPageContent(t, p, normalizeExpected(ext, "<p>Summary Next Line</p>\n\n<p>Some more text</p>\n"), ext)
 		checkPageSummary(t, p, normalizeExpected(ext, "<p>Summary Next Line</p>"), ext)
-		checkPageType(t, p, "page")
 	}
 
 	testAllMarkdownEnginesForPages(t, assertFunc, nil, simplePageWithSummaryDelimiter)
@@ -591,7 +582,6 @@ func TestPageWithSummaryParameter(t *testing.T) {
 		if ext != "ad" && ext != "rst" {
 			checkPageSummary(t, p, normalizeExpected(ext, "Page with summary parameter and <a href=\"http://www.example.com/\">a link</a>"), ext)
 		}
-		checkPageType(t, p, "page")
 	}
 
 	testAllMarkdownEnginesForPages(t, assertFunc, nil, simplePageWithSummaryParameter)
@@ -663,7 +653,6 @@ func TestPageWithShortCodeInSummary(t *testing.T) {
 		checkPageTitle(t, p, "Simple")
 		checkPageContent(t, p, normalizeExpected(ext, "<p>Summary Next Line. <figure> <img src=\"/not/real\"/> </figure> . More text here.</p><p>Some more text</p>"))
 		checkPageSummary(t, p, "Summary Next Line.  . More text here. Some more text")
-		checkPageType(t, p, "page")
 	}
 
 	testAllMarkdownEnginesForPages(t, assertFunc, nil, simplePageWithShortcodeInSummary)
@@ -713,8 +702,6 @@ func TestPageWithMoreTag(t *testing.T) {
 		checkPageTitle(t, p, "Simple")
 		checkPageContent(t, p, normalizeExpected(ext, "<p>Summary Same Line</p>\n\n<p>Some more text</p>\n"))
 		checkPageSummary(t, p, normalizeExpected(ext, "<p>Summary Same Line</p>"))
-		checkPageType(t, p, "page")
-
 	}
 
 	testAllMarkdownEnginesForPages(t, assertFunc, nil, simplePageWithSummaryDelimiterSameLine)