fix(open): guard linux/darwin VS Code probes against empty HOME

When HOME was unset, filepath.Join produced relative per-user paths (.local/bin/code, Applications/Visual Studio Code.app) that could match an unintended binary or directory in the working directory. Skip those entries when HOME is empty.

Author: dlevy-msft-sql

internal/tools/tool/vscode_darwin.go

@@ -21,11 +21,16 @@ func (t *VSCode) searchLocations() []string {
 		if build == "insiders" {
 			app = "Visual Studio Code - Insiders.app"
 		}
-		locations = append(locations,
-			filepath.Join("/", "Applications", app),
-			filepath.Join(userProfile, "Applications", app),
-			filepath.Join(userProfile, "Downloads", app),
-		)
+		locations = append(locations, filepath.Join("/", "Applications", app))
+		// Skip the per-user paths when $HOME is empty -- filepath.Join would
+		// produce a relative "Applications/..." that could match a directory
+		// in the working directory.
+		if userProfile != "" {
+			locations = append(locations,
+				filepath.Join(userProfile, "Applications", app),
+				filepath.Join(userProfile, "Downloads", app),
+			)
+		}
 	}
 	return locations
 }

internal/tools/tool/vscode_linux.go

@@ -23,7 +23,14 @@ func (t *VSCode) searchLocations() []string {
 		}
 		locations = append(locations,
 			filepath.Join("/", "usr", "bin", cli),
-			filepath.Join(userProfile, ".local", "bin", cli),
+		)
+		// Skip the per-user path when $HOME is empty -- filepath.Join would
+		// produce a relative ".local/bin/<cli>" that could match an unintended
+		// binary in the working directory.
+		if userProfile != "" {
+			locations = append(locations, filepath.Join(userProfile, ".local", "bin", cli))
+		}
+		locations = append(locations,
 			filepath.Join("/", "snap", "bin", cli),
 		)
 	}