[LTR] Update kernel.spec during rebases

When rebasing a CLK kernel onto a new LT kernel, update
kernel.spec to match (if it exists).

Update the kernel version strings and replace the changelog
with references to the upstream LT we are rebasing on and
the commits we apply on top of it.

Author: bmastbergen

lt_rebase.sh

@@ -148,4 +148,68 @@ if [ ! -z "$REPO_STATUS" ]; then
     git commit -m "[CIQ] $(git describe --tags --abbrev=0) - rebased configs"
 fi
 
+SPEC_FILE="./SPECS/kernel.spec"
+if [ -f "$SPEC_FILE" ] ; then
+    UPSTREAM_TAG=$(git describe --tags --abbrev=0)
+    if [ -z "$UPSTREAM_TAG" ]; then
+        echo "ERROR: Could not determine upstream tag via git describe. Cannot update spec."
+        exit 1
+    fi
+    FULL_KERNEL_VERSION=${UPSTREAM_TAG#v}
+    TAG_VERSION="${FULL_KERNEL_VERSION}-1"
+    NEW_TAG="ciq_kernel-${TAG_VERSION}"
+    DISTLOCALVERSION=${DISTLOCALVERSION:-".1.0.0"}
+    DIST=${DIST:-".el9_clk"}
+    SPECTARFILE_RELEASE=${TAG_VERSION}$DISTLOCALVERSION$DIST
+
+    echo "Updating kernel.spec version variables and changelog..."
+
+    # Update version variables
+    sed -i -e "s/^%define specrpmversion .*/%define specrpmversion $FULL_KERNEL_VERSION/" \
+           -e "s/^%define specversion .*/%define specversion $FULL_KERNEL_VERSION/" \
+           -e "s/^%define tarfile_release .*/%define tarfile_release $SPECTARFILE_RELEASE/" \
+           "$SPEC_FILE"
+
+    # Generate changelog
+    # Extract major version (e.g., 6 from 6.12.74)
+    MAJOR_VERSION=${FULL_KERNEL_VERSION%%.*}
+    CHANGELOG_DATE=$(date '+%a %b %d %Y')
+    CHANGELOG_HEADER="* $CHANGELOG_DATE $(git config user.name) <$(git config user.email)> - ${TAG_VERSION}${DISTLOCALVERSION}${DIST}"
+    TEMP_CHANGELOG=$(mktemp)
+    TEMP_COMMENTS=$(mktemp)
+
+    # Full changelog for new kernel version or initial spec update
+    echo "$CHANGELOG_HEADER" > "$TEMP_CHANGELOG"
+    echo "-- Rebased changes for Linux $FULL_KERNEL_VERSION (https://github.com/ctrliq/kernel-src-tree/releases/tag/$NEW_TAG)" >> "$TEMP_CHANGELOG"
+    git log --no-merges --pretty=format:"-- %s (%an)" ${UPSTREAM_TAG}..HEAD >> "$TEMP_CHANGELOG"
+    echo "" >> "$TEMP_CHANGELOG"
+    echo "-- Linux $FULL_KERNEL_VERSION (https://cdn.kernel.org/pub/linux/kernel/v$MAJOR_VERSION.x/ChangeLog-$FULL_KERNEL_VERSION)" >> "$TEMP_CHANGELOG"
+    echo "" >> "$TEMP_CHANGELOG"
+    echo "" >> "$TEMP_CHANGELOG"
+
+    # Extract trailing comments (lines starting with # after %changelog)
+    awk '/^%changelog$/,0 {if (/^#/ || /^###/) print}' "$SPEC_FILE" > "$TEMP_COMMENTS"
+
+    # Rebuild changelog section
+    if ! grep -q '^%changelog$' "$SPEC_FILE"; then
+        echo "ERROR: %changelog section not found in $SPEC_FILE. Cannot update spec."
+        exit 1
+    fi
+    # Remove everything from %changelog onwards
+    sed -i '/^%changelog$/q' "$SPEC_FILE"
+
+    # Add new changelog entry
+    cat "$TEMP_CHANGELOG" >> "$SPEC_FILE"
+
+    # Add trailing comments if any
+    if [ -s "$TEMP_COMMENTS" ]; then
+        cat "$TEMP_COMMENTS" >> "$SPEC_FILE"
+    fi
+
+    rm -f "$TEMP_CHANGELOG" "$TEMP_COMMENTS"
 
+    git add "$SPEC_FILE"
+    git commit -m "[CIQ] $(git describe --tags --abbrev=0) - updated spec"
+
+    echo "Spec file updated successfully"
+fi