Misc remote HTTP/content adapter enhancements

* Recover from server errors
* Improve go adapter rebuilds when adding new content

See #12502
Fixes #12570

4 files changed, 33 insertions, 2 deletions

diff --git a/commands/hugobuilder.go b/commands/hugobuilder.go
index 99bd8a04a..d77f1f178 100644
--- a/commands/hugobuilder.go
+++ b/commands/hugobuilder.go
@@ -345,6 +345,7 @@ func (c *hugoBuilder) newWatcher(pollIntervalStr string, dirList ...string) (*wa
 		for {
 			select {
 			case changes := <-c.r.changesFromBuild:
+				c.errState.setBuildErr(nil)
 				unlock, err := h.LockBuild()
 				if err != nil {
 					c.r.logger.Errorln("Failed to acquire a build lock: %s", err)
@@ -356,7 +357,9 @@ func (c *hugoBuilder) newWatcher(pollIntervalStr string, dirList ...string) (*wa
 					c.r.logger.Errorln("Error while watching:", err)
 				}
 				if c.s != nil && c.s.doLiveReload {
-					if c.changeDetector == nil || len(c.changeDetector.changed()) > 0 {
+					doReload := c.changeDetector == nil || len(c.changeDetector.changed()) > 0
+					doReload = doReload || c.showErrorInBrowser && c.errCount() > 0
+					if doReload {
 						livereload.ForceRefresh()
 					}
 				}
diff --git a/hugolib/content_map.go b/hugolib/content_map.go
index 6ab945209..55c96c9a0 100644
--- a/hugolib/content_map.go
+++ b/hugolib/content_map.go
@@ -386,6 +386,21 @@ func (m *pageMap) addPagesFromGoTmplFi(fi hugofs.FileMetaInfo, buildConfig *Buil
 							pt.AddChange(n.GetIdentity())
 						} else {
 							pt.AddChange(u.GetIdentity())
+							// New content not in use anywhere.
+							// To make sure that these gets listed in any site.RegularPages ranges or similar
+							// we could invalidate everything, but first try to collect a sample set
+							// from the surrounding pages.
+							var surroundingIDs []identity.Identity
+							ids := h.pageTrees.collectIdentitiesSurrounding(pi.Base(), 10)
+							if len(ids) > 0 {
+								surroundingIDs = append(surroundingIDs, ids...)
+							} else {
+								// No surrounding pages found, so invalidate everything.
+								surroundingIDs = []identity.Identity{identity.GenghisKhan}
+							}
+							for _, id := range surroundingIDs {
+								pt.AddChange(id)
+							}
 						}
 					}
 
diff --git a/hugolib/hugo_sites_build.go b/hugolib/hugo_sites_build.go
index fe05f5174..12eb6a5f8 100644
--- a/hugolib/hugo_sites_build.go
+++ b/hugolib/hugo_sites_build.go
@@ -244,9 +244,13 @@ func (h *HugoSites) process(ctx context.Context, l logg.LevelLogger, config *Bui
 	}
 
 	if len(events) > 0 {
-		// This is a rebuild
+		// This is a rebuild triggered from file events.
 		return h.processPartialFileEvents(ctx, l, config, init, events)
 	} else if len(config.WhatChanged.Changes()) > 0 {
+		// Rebuild triggered from remote events.
+		if err := init(config); err != nil {
+			return err
+		}
 		return h.processPartialRebuildChanges(ctx, l, config)
 	}
 	return h.processFull(ctx, l, config)
diff --git a/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go b/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go
index f351cbb98..3c50f87f7 100644
--- a/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go
+++ b/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go
@@ -80,6 +80,7 @@ Pfile Content
 {{ $.AddPage  (dict "kind" "page" "path" "p2" "title" "p2title" "dates" $dates "content" $contentHTML ) }}
 {{ $.AddPage  (dict "kind" "page" "path" "p3" "title" "p3title" "dates" $dates "content" $contentMarkdownDefault "draft" false ) }}
 {{ $.AddPage  (dict "kind" "page" "path" "p4" "title" "p4title" "dates" $dates "content" $contentMarkdownDefault "draft" $data.draft ) }}
+ADD_MORE_PLACEHOLDER
 
 
 {{ $resourceContent := dict "value" $dataResource }}
@@ -279,6 +280,14 @@ func TestPagesFromGoTmplRemovePage(t *testing.T) {
 	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
 }
 
+func TestPagesFromGoTmplAddPage(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("content/docs/_content.gotmpl", "ADD_MORE_PLACEHOLDER", `{{ $.AddPage  (dict "kind" "page" "path" "page_added" "title" "page_added_title" "dates" $dates "content" $contentHTML ) }}`).Build()
+	b.AssertFileExists("public/docs/page_added/index.html", true)
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|p4title:/docs/p4|page_added_title:/docs/page_added|pfile:/docs/pfile|$")
+}
+
 func TestPagesFromGoTmplDraftPage(t *testing.T) {
 	t.Parallel()
 	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)