Fix threading related issues related to warping in GTI driver

[rouault]

Fixes #14262

Two separate issues:

• potential dead lock in warper
• crash in some scenario in error handling logic

[rouault]

The backport to release/3.12 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply f14e754909... Tidy up CPLErrorAccumulator::Context design
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"

stdout

Auto-merging alg/gdalwarpkernel.cpp
Auto-merging autotest/alg/warp.py
[backport-14263-to-release/3.12 f2fb62a54b] Warping: more reliable progress interruption detection in multi-threaded case
 Author: Even Rouault <even.rouault@spatialys.com>
 Date: Tue Mar 31 13:25:41 2026 +0200
 2 files changed, 14 insertions(+), 1 deletion(-)
Auto-merging alg/gdalwarpkernel.cpp
[backport-14263-to-release/3.12 4be1c0263d] Warper: avoid potential dead-lock, when warping is done from a worker thread of the GDAL global thread pool
 Author: Even Rouault <even.rouault@spatialys.com>
 Date: Tue Mar 31 03:58:26 2026 +0200
 1 file changed, 12 insertions(+), 5 deletions(-)
Auto-merging autotest/cpp/test_cpl.cpp
Auto-merging port/cpl_error.cpp
[backport-14263-to-release/3.12 aa76f0ffa0] Error handling: avoid potential crash when a debug message ...
 Author: Even Rouault <even.rouault@spatialys.com>
 Date: Tue Mar 31 04:00:40 2026 +0200
 2 files changed, 47 insertions(+)
Auto-merging port/cpl_error.cpp
CONFLICT (content): Merge conflict in port/cpl_error.cpp
Auto-merging port/cpl_error_internal.h

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release/3.12 release/3.12
# Navigate to the new working tree
cd .worktrees/backport-release/3.12
# Create a new branch
git switch --create backport-14263-to-release/3.12
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick d75e9739aa7fea6ed2712a414ffb9b60f86b6d1f,45bf064f6e508992f5ffa6854da67bce13198b5a,bbfdf88cd1de5c969d5adedb076a6aa8dcf2319f,f14e75490904ed60458c28702fc708e0c53ce09f,1edd2321f5e313e09e8d5a4cceba1943f7082a2f,37bd77befaf02233f7385c077be8ffbf424ab5f0
# Push it to GitHub
git push --set-upstream origin backport-14263-to-release/3.12
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release/3.12

Then, create a pull request where the base branch is release/3.12 and the compare/head branch is backport-14263-to-release/3.12.

[rouault]

3.12 backport in #14269