From 45a3bdb584d53c61d3ea869d0a5d44ae02feae4a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20=C4=8Ciha=C5=99?= <michal@cihar.com>
Date: Fri, 8 Sep 2023 13:25:05 +0200
Subject: [PATCH] formatter: Fix display of diff inside a placeable

Fixes #9821
---
 weblate/trans/templatetags/translations.py | 43 ++++++++++++++++++++--
 1 file changed, 40 insertions(+), 3 deletions(-)

diff --git a/weblate/trans/templatetags/translations.py b/weblate/trans/templatetags/translations.py
index 6f5b0d82dd45..c4e7e4df23df 100644
--- a/weblate/trans/templatetags/translations.py
+++ b/weblate/trans/templatetags/translations.py
@@ -139,6 +139,7 @@ def parse_diff(self):  # noqa: C901
                 formatter.parse()
                 self.tags[offset].append(f"<del>{formatter.format()}</del>")
             elif op == self.differ.DIFF_INSERT:
+                end = offset + len(data)
                 # Rearrange space highlighting
                 move_space = False
                 start_space = -1
@@ -172,10 +173,46 @@ def parse_diff(self):  # noqa: C901
                     self.tags[offset].append("<ins>")
                 if move_space:
                     self.tags[offset].append(SPACE_START)
-                offset += len(data)
-                self.tags[offset].append("</ins>")
+                self.tags[end].append("</ins>")
                 if start_space != -1:
-                    self.tags[offset].append(SPACE_START)
+                    self.tags[end].append(SPACE_START)
+
+                # Rearange other tags
+                open_tags = 0
+                process = False
+                for i in range(offset, end + 1):
+                    remove = []
+                    for pos, tag in enumerate(self.tags[i]):
+                        if not process:
+                            if tag.startswith("<ins"):
+                                process = True
+                            continue
+                        if tag.startswith("</ins>"):
+                            break
+                        if tag.startswith("<span"):
+                            open_tags += 1
+                        elif tag.startswith("</span"):
+                            if open_tags == 0:
+                                # Remove tags spanning over <ins>
+                                remove.append(pos)
+                                found = None
+                                for back in range(offset - 1, 0, -1):
+                                    for child_pos, child in reversed(
+                                        list(enumerate(self.tags[back]))
+                                    ):
+                                        if child.startswith("<span"):
+                                            found = child_pos
+                                            break
+                                    if found is not None:
+                                        del self.tags[back][found]
+                                        break
+                            else:
+                                open_tags -= 1
+                    # Remove closing tags (do this outside the loop)
+                    for pos in reversed(remove):
+                        del self.tags[i][pos]
+
+                offset = end
             elif op == self.differ.DIFF_EQUAL:
                 offset += len(data)