[GITEA] Find README.md for user profiles case insensitively

When trying to find a `README.md` in a `.profile` repo, do so case
insensitively. This change does not make it possible to render readmes
in formats other than Markdown, it just removes the hard-coded
"README.md".

Also adds a few tests to make sure the change works.

Fixes #1494.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit edd219d8e9d69becb9814ab0a8359555e80fcd4f)
(cherry picked from commit 2c0105ef17b9673e6892a66aa689af7c5c87b8a1)
(cherry picked from commit 3975a9f3aaf8ed3ceb5788abc325dbe8e89225d3)
(cherry picked from commit dee4a18423151ac7f22221e6fce12d863921c200)
(cherry picked from commit 60aee6370fb15b12fffc6f29582dd4a235f87d94)

1 files changed, 21 insertions, 0 deletions

diff --git a/modules/git/tree_blob.go b/modules/git/tree_blob.go
index 31d9f3d73b..e60c1f915b 100644
--- a/modules/git/tree_blob.go
+++ b/modules/git/tree_blob.go
@@ -1,9 +1,12 @@
 // Copyright 2015 The Gogs Authors. All rights reserved.
 // Copyright 2019 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
 // SPDX-License-Identifier: MIT
 
 package git
 
+import "strings"
+
 // GetBlobByPath get the blob object according the path
 func (t *Tree) GetBlobByPath(relpath string) (*Blob, error) {
 	entry, err := t.GetTreeEntryByPath(relpath)
@@ -17,3 +20,21 @@ func (t *Tree) GetBlobByPath(relpath string) (*Blob, error) {
 
 	return nil, ErrNotExist{"", relpath}
 }
+
+// GetBlobByFoldedPath returns the blob object at relpath, regardless of the
+// case of relpath. If there are multiple files with the same case-insensitive
+// name, the first one found will be returned.
+func (t *Tree) GetBlobByFoldedPath(relpath string) (*Blob, error) {
+	entries, err := t.ListEntries()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, entry := range entries {
+		if strings.EqualFold(entry.Name(), relpath) {
+			return t.GetBlobByPath(entry.Name())
+		}
+	}
+
+	return nil, ErrNotExist{"", relpath}
+}