Fix submodule parsing

(cherry picked from commit 33850a83fe4ebd23a762a7aac81614c42e303bfa)

This really is just the cherry pick of 407b6e6dfc7ee9ebb8a16c7f1a786e4c24d0516e
which is the first commit of the pull request, the one with the
change. The rest of the changes is a refactor that is unrelated to the
bug fix.

Conflicts:
	modules/git/commit_test.go
  trivial context conflict

modules/git/commit.go

@@ -17,6 +17,8 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/util"
+
+	"github.com/go-git/go-git/v5/config"
 )
 
 // Commit represents a git commit.
@@ -365,37 +367,32 @@ func (c *Commit) GetSubModules() (*ObjectCache, error) {
 		return nil, err
 	}
 
-	rd, err := entry.Blob().DataAsync()
+	content, err := entry.Blob().GetBlobContent(10 * 1024)
 	if err != nil {
 		return nil, err
 	}
 
-	defer rd.Close()
-	scanner := bufio.NewScanner(rd)
-	c.submoduleCache = newObjectCache()
-	var ismodule bool
-	var path string
-	for scanner.Scan() {
-		if strings.HasPrefix(scanner.Text(), "[submodule") {
-			ismodule = true
-			continue
-		}
-		if ismodule {
-			fields := strings.Split(scanner.Text(), "=")
-			k := strings.TrimSpace(fields[0])
-			if k == "path" {
-				path = strings.TrimSpace(fields[1])
-			} else if k == "url" {
-				c.submoduleCache.Set(path, &SubModule{path, strings.TrimSpace(fields[1])})
-				ismodule = false
-			}
-		}
+	c.submoduleCache, err = parseSubmoduleContent([]byte(content))
+	if err != nil {
+		return nil, err
 	}
-	if err = scanner.Err(); err != nil {
-		return nil, fmt.Errorf("GetSubModules scan: %w", err)
+	return c.submoduleCache, nil
+}
+
+func parseSubmoduleContent(bs []byte) (*ObjectCache, error) {
+	cfg := config.NewModules()
+	if err := cfg.Unmarshal(bs); err != nil {
+		return nil, err
+	}
+	submoduleCache := newObjectCache()
+	if len(cfg.Submodules) == 0 {
+		return nil, fmt.Errorf("no submodules found")
+	}
+	for _, subModule := range cfg.Submodules {
+		submoduleCache.Set(subModule.Path, subModule.URL)
 	}
 
-	return c.submoduleCache, nil
+	return submoduleCache, nil
 }
 
 // GetSubModule get the sub module according entryname

modules/git/commit_test.go

@@ -369,3 +369,33 @@ func TestParseCommitRenames(t *testing.T) {
 		assert.Equal(t, testcase.renames, renames)
 	}
 }
+
+func Test_parseSubmoduleContent(t *testing.T) {
+	submoduleFiles := []struct {
+		fileContent  string
+		expectedPath string
+		expectedURL  string
+	}{
+		{
+			fileContent: `[submodule "jakarta-servlet"]
+url = ../../ALP-pool/jakarta-servlet
+path = jakarta-servlet`,
+			expectedPath: "jakarta-servlet",
+			expectedURL:  "../../ALP-pool/jakarta-servlet",
+		},
+		{
+			fileContent: `[submodule "jakarta-servlet"]
+path = jakarta-servlet
+url = ../../ALP-pool/jakarta-servlet`,
+			expectedPath: "jakarta-servlet",
+			expectedURL:  "../../ALP-pool/jakarta-servlet",
+		},
+	}
+	for _, kase := range submoduleFiles {
+		submodule, err := parseSubmoduleContent([]byte(kase.fileContent))
+		require.NoError(t, err)
+		v, ok := submodule.Get(kase.expectedPath)
+		assert.True(t, ok)
+		assert.Equal(t, kase.expectedURL, v)
+	}
+}