Use external diff command in stashes panel

This was forgotten in 6266e19623.

pkg/commands/git_commands/stash.go

@@ -81,11 +81,15 @@ func (self *StashCommands) Hash(index int) (string, error) {
 }
 
 func (self *StashCommands) ShowStashEntryCmdObj(index int) *oscommands.CmdObj {
+	extDiffCmd := self.UserConfig().Git.Paging.ExternalDiffCommand
+
 	// "-u" is the same as "--include-untracked", but the latter fails in older git versions for some reason
 	cmdArgs := NewGitCmd("stash").Arg("show").
 		Arg("-p").
 		Arg("--stat").
 		Arg("-u").
+		ConfigIf(extDiffCmd != "", "diff.external="+extDiffCmd).
+		ArgIfElse(extDiffCmd != "", "--ext-diff", "--no-ext-diff").
 		Arg(fmt.Sprintf("--color=%s", self.UserConfig().Git.Paging.ColorArg)).
 		Arg(fmt.Sprintf("--unified=%d", self.UserConfig().Git.DiffContextSize)).
 		ArgIf(self.UserConfig().Git.IgnoreWhitespaceInDiffView, "--ignore-all-space").

pkg/commands/git_commands/stash_test.go

@@ -103,6 +103,7 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 		contextSize         uint64
 		similarityThreshold int
 		ignoreWhitespace    bool
+		extDiffCmd          string
 		expected            []string
 	}
 
@@ -113,7 +114,7 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 			contextSize:         3,
 			similarityThreshold: 50,
 			ignoreWhitespace:    false,
-			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--color=always", "--unified=3", "--find-renames=50%", "refs/stash@{5}"},
+			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--no-ext-diff", "--color=always", "--unified=3", "--find-renames=50%", "refs/stash@{5}"},
 		},
 		{
 			testName:            "Show diff with custom context size",
@@ -121,7 +122,7 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 			contextSize:         77,
 			similarityThreshold: 50,
 			ignoreWhitespace:    false,
-			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--color=always", "--unified=77", "--find-renames=50%", "refs/stash@{5}"},
+			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--no-ext-diff", "--color=always", "--unified=77", "--find-renames=50%", "refs/stash@{5}"},
 		},
 		{
 			testName:            "Show diff with custom similarity threshold",
@@ -129,7 +130,16 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 			contextSize:         3,
 			similarityThreshold: 33,
 			ignoreWhitespace:    false,
-			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--color=always", "--unified=3", "--find-renames=33%", "refs/stash@{5}"},
+			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--no-ext-diff", "--color=always", "--unified=3", "--find-renames=33%", "refs/stash@{5}"},
+		},
+		{
+			testName:            "Show diff with external diff command",
+			index:               5,
+			contextSize:         3,
+			similarityThreshold: 50,
+			ignoreWhitespace:    false,
+			extDiffCmd:          "difft --color=always",
+			expected:            []string{"git", "-C", "/path/to/worktree", "-c", "diff.external=difft --color=always", "stash", "show", "-p", "--stat", "-u", "--ext-diff", "--color=always", "--unified=3", "--find-renames=50%", "refs/stash@{5}"},
 		},
 		{
 			testName:            "Default case",
@@ -137,7 +147,7 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 			contextSize:         3,
 			similarityThreshold: 50,
 			ignoreWhitespace:    true,
-			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--color=always", "--unified=3", "--ignore-all-space", "--find-renames=50%", "refs/stash@{5}"},
+			expected:            []string{"git", "-C", "/path/to/worktree", "stash", "show", "-p", "--stat", "-u", "--no-ext-diff", "--color=always", "--unified=3", "--ignore-all-space", "--find-renames=50%", "refs/stash@{5}"},
 		},
 	}
 
@@ -147,6 +157,7 @@ func TestStashStashEntryCmdObj(t *testing.T) {
 			userConfig.Git.IgnoreWhitespaceInDiffView = s.ignoreWhitespace
 			userConfig.Git.DiffContextSize = s.contextSize
 			userConfig.Git.RenameSimilarityThreshold = s.similarityThreshold
+			userConfig.Git.Paging.ExternalDiffCommand = s.extDiffCmd
 			repoPaths := RepoPaths{
 				worktreePath: "/path/to/worktree",
 			}