doc: allow commits to suppress the schema checks.

The stupid requirement for JSON commas combines with our inability to
annotate the removal or introduction of enum values and our naive
check here, to produce a false positive.  Allow commit messages to
suppress.

No-schema-diff-check: removed enum `websocket` as value type.

Signed-off-by: Rusty Russell <[email protected]>

doc/Makefile

@@ -230,18 +230,23 @@ doc/index.rst: $(MANPAGES:=.md)
 # For CI to (very roughly!) check that we only deprecated fields, or labelled added ones
 # When running on GitHub (CI=true), we need to fetch origin/master
 schema-added-check:
-	@if ! test -z $$CI; then git fetch origin master; fi; \
-	if git diff origin/master -- doc/schemas | grep -q '^+.*{' && ! git diff origin/master -- doc/schemas | grep -q '^+.*"added"'; then \
-		git diff origin/master -- doc/schemas; \
+	@if ! test -z $$CI; then git fetch origin master; ROOT=FETCH_HEAD; else ROOT=master; fi; \
+	if git show --format=%B -s $$ROOT.. | grep -q '^No-schema-diff-check'; then echo $@ suppressed; exit 0; fi; \
+	if git diff $$ROOT -- doc/schemas | grep -q '^+.*{' && ! git diff $$ROOT -- doc/schemas | grep -q '^+.*"added"'; then \
+		git diff $$ROOT -- doc/schemas; \
 		echo 'New schema fields must have "added": "vNEXTVERSION"' >&2; exit 1; \
 	fi
 schema-removed-check:
-	@if ! test -z $$CI; then git fetch origin master; fi; \
-	if git diff origin/master -- doc/schemas | grep -q '^-.*{' && ! git diff origin/master -- doc/schemas | grep -q '^-.*"deprecated"' && ! git diff origin/master -- doc/schemas | grep -q '^-.*EXPERIMENTAL_FEATURES'; then \
-		git diff origin/master -- doc/schemas ; \
+	@if ! test -z $$CI; then git fetch origin master; ROOT=FETCH_HEAD; else ROOT=master; fi; \
+	if git show --format=%B -s $$ROOT.. | grep -q '^No-schema-diff-check'; then echo $@ suppressed; exit 0; fi; \
+	if git diff $$ROOT -- doc/schemas | grep -q '^-.*{' && ! git diff $$ROOT -- doc/schemas | grep -q '^-.*"deprecated"' && ! git diff $$ROOT -- doc/schemas | grep -q '^-.*EXPERIMENTAL_FEATURES'; then \
+		git diff $$ROOT -- doc/schemas ; \
 		echo 'Schema fields must be "deprecated", with version, not removed' >&2; exit 1; \
 	fi
 
-schema-diff-check: schema-added-check schema-removed-check
+show-diff:
+	@if ! test -z $$CI; then git fetch origin master; ROOT=FETCH_HEAD; else ROOT=master; fi; echo "DIFF from $$ROOT to here:"; git show --format=%B $$ROOT..
+
+schema-diff-check: show-diff schema-added-check schema-removed-check
 
 check-source: schema-diff-check