Blender Finder: allow passing the directory instead of the executable

Blender Finder now understands that directory paths should be suffixed
with `blender` (Linux, macOS) or `blender.exe` (Windows).

Giving the Setup Assistant a path like `C:\Program files\Blender
Foundation\Blender 3.2` will now just work. This is considerably simpler
for many users, as copy-pasting a directory from a file explorer is
simpler than obtaining/typing the path to the executable.

internal/find_blender/find_blender.go

@@ -6,7 +6,9 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"os/exec"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -58,8 +60,8 @@ func CheckBlender(ctx context.Context, exename string) (CheckBlenderResult, erro
 	}
 
 	if crosspath.Dir(exename) != "." {
-		// exename is some form of path, see if it works directly as executable.
-		return getResultWithVersion(ctx, exename, exename, api.BlenderPathSourceInputPath)
+		// exename is some form of path, see if it works for us.
+		return checkBlenderAtPath(ctx, exename)
 	}
 
 	// Try to find exename on $PATH
@@ -70,6 +72,25 @@ func CheckBlender(ctx context.Context, exename string) (CheckBlenderResult, erro
 	return getResultWithVersion(ctx, exename, fullPath, api.BlenderPathSourcePathEnvvar)
 }
 
+func checkBlenderAtPath(ctx context.Context, path string) (CheckBlenderResult, error) {
+	stat, err := os.Stat(path)
+	if err != nil {
+		return CheckBlenderResult{}, err
+	}
+	if !stat.IsDir() {
+		// Simple case, it's not a directory so let's just try and execute it.
+		return getResultWithVersion(ctx, path, path, api.BlenderPathSourceInputPath)
+	}
+
+	// Try appending the Blender executable name.
+	log.Debug().
+		Str("path", path).
+		Str("executable", blenderExeName).
+		Msg("blender finder: given path is directory, going to find Blender executable")
+	exepath := filepath.Join(path, blenderExeName)
+	return getResultWithVersion(ctx, path, exepath, api.BlenderPathSourceInputPath)
+}
+
 // getResultWithVersion tries to run the command to get Blender's version.
 // The result is returned as a `CheckBlenderResult` struct.
 func getResultWithVersion(

internal/find_blender/nonwindows.go

@@ -4,6 +4,8 @@ package find_blender
 
 // SPDX-License-Identifier: GPL-3.0-or-later
 
+const blenderExeName = "blender"
+
 // fileAssociation isn't implemented on non-Windows platforms.
 func fileAssociation() (string, error) {
 	return "", ErrNotAvailable

internal/find_blender/windows.go

@@ -14,6 +14,8 @@ import (
 	"unsafe"
 )
 
+const blenderExeName = "blender.exe"
+
 // fileAssociation returns the full path of `blender.exe` associated with ".blend" files.
 func fileAssociation() (string, error) {
 	exe, err := getFileAssociation(".blend")

web/app/src/views/SetupAssistantView.vue

@@ -182,7 +182,7 @@
                 v-model="customBlenderExe"
                 :class="{'is-invalid': blenderExeCheckResult != null && !blenderExeCheckResult.is_usable}"
                 type="text"
-                placeholder="Path to Blender executable"
+                placeholder="Path to Blender"
               >
               <p v-if="isBlenderExeChecking" class="is-in-progress">Checking...</p>
               <p v-if="blenderExeCheckResult != null && !blenderExeCheckResult.is_usable" class="check-failed">