Fix bug saving tags in file sequences using -save-as "{tag}_1.png"

Now the equivalent was "{tag}_{frame1}.png", but it looks like a
regression reported here https://community.aseprite.org/t/17253 were
it was possible to just specify the frame number as in "{tag}_1.png"

src/app/file/file.cpp

@@ -682,6 +682,12 @@ FileOp* FileOp::createSaveDocumentOperation(const Context* context,
         false,                      // Doesn't have layers
         false);                     // Doesn't have tags
     }
+    // If the filename format is given, we have to check if the
+    // {frame} is specified, or in other case, if it's something like
+    // "..._1.png", replace the it with "..._{frame1}.png"
+    else if (fop->m_roi.selectedFrames().size() > 1) {
+      fn_format = replace_frame_number_with_frame_format(fn_format);
+    }
 
     frame_t outputFrame = 0;
 

src/app/filename_formatter.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2022  Igara Studio S.A.
+// Copyright (C) 2022-2023  Igara Studio S.A.
 // Copyright (C) 2001-2017  David Capello
 //
 // This program is distributed under the terms of
@@ -50,6 +50,24 @@ static bool replace_frame(const char* frameKey, // E.g. = "{frame"
     return false;
 }
 
+static bool autodetect_frame_format(const std::string& filename,
+                                    std::string& left,
+                                    std::string& frameFormat,
+                                    std::string& right,
+                                    int& frameBase)
+{
+  int frameWidth = 0;
+  frameBase = split_filename(filename, left, right, frameWidth);
+  if (frameBase >= 0) {
+    std::vector<char> buf(32);
+    std::sprintf(&buf[0], "{frame%0*d}", frameWidth, frameBase);
+    frameFormat = std::string(&buf[0]);
+    return true;
+  }
+  else
+    return false;
+}
+
 bool get_frame_info_from_filename_format(
   const std::string& format, int* frameBase, int* width)
 {
@@ -179,16 +197,14 @@ std::string get_default_filename_format(
     // Check if we already have a frame number at the end of the
     // filename (e.g. output01.png)
     int frameBase = -1, frameWidth = 0;
-    std::string left, right;
+    std::string left, frameFormat, right;
-    if (autoFrameFromLastDigit)
-      frameBase = split_filename(filename, left, right, frameWidth);
-    if (frameBase >= 0) {
-      std::vector<char> buf(32);
-      std::sprintf(&buf[0], "{frame%0*d}", frameWidth, frameBase);
 
+    if (autoFrameFromLastDigit &&
+        autodetect_frame_format(
+          filename, left, frameFormat, right, frameBase)) {
       if (hasLayer || hasTag)
         format += " ";
-      format += &buf[0];
+      format += frameFormat;
 
       // Remove the frame number from the filename part.
       filename = left;
@@ -245,4 +261,26 @@ std::string get_default_tagname_format_for_sheet()
   return "{tag}";
 }
 
+std::string replace_frame_number_with_frame_format(const std::string& filename)
+{
+  std::string result = filename;
+
+  if (is_static_image_format(filename) &&
+      filename.find("{frame") == std::string::npos &&
+      filename.find("{tagframe") == std::string::npos) {
+    std::string left, frameFormat, right;
+    int frameBase = -1;
+
+    if (!autodetect_frame_format(
+          filename, left, frameFormat, right, frameBase)) {
+      frameFormat = "{frame1}";
+    }
+    result = left;
+    result += frameFormat;
+    result += right;
+  }
+
+  return result;
+}
+
 } // namespace app

src/app/filename_formatter.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2022  Igara Studio S.A.
+// Copyright (C) 2022-2023  Igara Studio S.A.
 // Copyright (C) 2001-2017  David Capello
 //
 // This program is distributed under the terms of
@@ -119,6 +119,17 @@ namespace app {
 
   std::string get_default_tagname_format_for_sheet();
 
+  // Replaces "sprite1.png" with "sprite{frame1}.png". It's used to
+  // enable saving a sequence of images when the filename format
+  // doesn't specify {frame} but has some other formatting.
+  // E.g. -save-as "{tag}-1.png" will not use the default filename
+  // format (because the format is already specified in the filename,
+  // at least partially) but it still requires the {frame} format to
+  // avoid saving all frames into "...-1.png", so the result in this
+  // case must be: "{tag}-{frame1}.png".
+  std::string replace_frame_number_with_frame_format(
+    const std::string& filename);
+
 } // namespace app
 
 #endif

src/app/filename_formatter_tests.cpp

@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2023  Igara Studio S.A.
 // Copyright (C) 2001-2016  David Capello
 //
 // This program is distributed under the terms of
@@ -233,3 +234,20 @@ TEST(FilenameFormatter, DefaultFormat)
   EXPECT_EQ("{path}/{title} #{tag} {frame}.{extension}", get_default_filename_format(fn, true, true, false, true));
   EXPECT_EQ("/path/hello1.png", fn);
 }
+
+TEST(FilenameFormatter, DetectFrame)
+{
+  std::string fn;
+
+  fn = "/path/hello.png";
+  EXPECT_EQ("/path/hello{frame1}.png", replace_frame_number_with_frame_format(fn));
+
+  fn = "/path/hello0.png";
+  EXPECT_EQ("/path/hello{frame0}.png", replace_frame_number_with_frame_format(fn));
+
+  fn = "/path/hello1.png";
+  EXPECT_EQ("/path/hello{frame1}.png", replace_frame_number_with_frame_format(fn));
+
+  fn = "/path/hello002.png";
+  EXPECT_EQ("/path/hello{frame002}.png", replace_frame_number_with_frame_format(fn));
+}

tests/cli/save-as.sh

@@ -1,5 +1,5 @@
 #! /bin/bash
-# Copyright (C) 2018-2021 Igara Studio S.A.
+# Copyright (C) 2018-2023 Igara Studio S.A.
 
 function list_files() {
     oldwd=$(pwd $PWDARG)
@@ -276,3 +276,29 @@ expect "groups2-1.png
 groups3abc-1.png
 link-1.png
 link-2.png" "list_files $d"
+
+# Test regression with --save-as {tag}_1.png to interpret 1 as {frame1}
+# https://community.aseprite.org/t/17253
+
+d=$t/save-as-1-as-frame1-ok
+$ASEPRITE -b sprites/1empty3.aseprite \
+             -save-as "$d/{tag}-{frame1}.png" || exit 1
+expect "a-1.png
+a-2.png
+b-1.png" "list_files $d"
+
+d=$t/save-as-1-as-frame1-regression
+$ASEPRITE -b sprites/1empty3.aseprite \
+             -save-as "$d/{tag}-1.png" || exit 1
+expect "a-1.png
+a-2.png
+b-1.png" "list_files $d"
+
+# Test that -save-as {tag}.png will save with the frame number when needed
+
+d=$t/save-as-with-format-but-without-frame
+$ASEPRITE -b sprites/1empty3.aseprite \
+             -save-as "$d/{tag}.png" || exit 1
+expect "a1.png
+a2.png
+b.png" "list_files $d"