Fossil SCM

More reliably work around the problem experienced by the previous commit. Not sure if this is the right long-term solution since we seem to have an architectural problem: at least one of Fossil's custom SQL functions can change the schema (in this case, by creating a temporary table), thereby invalidating a prepared statement while it is running. See the comment in checkin.c for a bit more information. Of course, there are rearrangements that avoid the issue, but it is certainly a trap for the unwary.

andygoth 2016-11-06 20:19 UTC andygoth-changes

Commit 5258a43d78fd433daa4ed36cae21b1d7e46c4efd

Parent 9d5de8d702e8b00…

2 files changed +6 -13 +2 -2

~ src/checkin.c ~ src/descendants.c

M src/checkin.c

+6 -13

		--- src/checkin.c
		+++ src/checkin.c
		@@ -173,23 +173,16 @@
173	173	flags & C_MTIME ? "datetime(mtime, 'unixepoch', toLocal())" : "''",
174	174	flags & C_SIZE ? "size" : "0",
175	175	fossil_all_reserved_names(0), blob_sql_text(&where));
176	176	}
177	177
178		-#if 1
179		- /* SQLITE BUG WORKAROUND??? */
180		- /* If I step the query sans the ORDER BY clause, then I can run the full query
181		- * without incident. But if I delete this workaround and run the query
182		- * normally, I get SQLITE_ABORT due to ROLLBACK, which makes no sense. */
183		- db_prepare(&q, "%s", blob_sql_text(&sql));
184		- if( (flags & C_ALL) && (flags & C_MTIME) ){
185		- db_bind_int(&q, ":vid", db_lget_int("checkout", 0));
186		- }
187		- db_step(&q);
188		- db_finalize(&q);
189		- /* SQLITE BUG WORKAROUND??? */
190		-#endif
	178	+ /* Pre-create the "ok" temporary table so the checkin_mtime() SQL function
	179	+ * does not lead to SQLITE_ABORT_ROLLBACK during execution of the OP_OpenRead
	180	+ * SQLite opcode. checkin_mtime() calls mtime_of_manifest_file() which
	181	+ * creates a temporary table if it doesn't already exist, thus invalidating
	182	+ * the prepared statement in the middle of its execution. */
	183	+ db_multi_exec("CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY)");
191	184
192	185	/* Append an ORDER BY clause then compile the query. */
193	186	blob_append_sql(&sql, " ORDER BY pathname");
194	187	db_prepare(&q, "%s", blob_sql_text(&sql));
195	188	blob_reset(&sql);
196	189

	--- src/checkin.c
	+++ src/checkin.c
	@@ -173,23 +173,16 @@
173	flags & C_MTIME ? "datetime(mtime, 'unixepoch', toLocal())" : "''",
174	flags & C_SIZE ? "size" : "0",
175	fossil_all_reserved_names(0), blob_sql_text(&where));
176	}
177
178	#if 1
179	/* SQLITE BUG WORKAROUND??? */
180	/* If I step the query sans the ORDER BY clause, then I can run the full query
181	* without incident. But if I delete this workaround and run the query
182	* normally, I get SQLITE_ABORT due to ROLLBACK, which makes no sense. */
183	db_prepare(&q, "%s", blob_sql_text(&sql));
184	if( (flags & C_ALL) && (flags & C_MTIME) ){
185	db_bind_int(&q, ":vid", db_lget_int("checkout", 0));
186	}
187	db_step(&q);
188	db_finalize(&q);
189	/* SQLITE BUG WORKAROUND??? */
190	#endif
191
192	/* Append an ORDER BY clause then compile the query. */
193	blob_append_sql(&sql, " ORDER BY pathname");
194	db_prepare(&q, "%s", blob_sql_text(&sql));
195	blob_reset(&sql);
196

	--- src/checkin.c
	+++ src/checkin.c
	@@ -173,23 +173,16 @@
173	flags & C_MTIME ? "datetime(mtime, 'unixepoch', toLocal())" : "''",
174	flags & C_SIZE ? "size" : "0",
175	fossil_all_reserved_names(0), blob_sql_text(&where));
176	}
177
178	/* Pre-create the "ok" temporary table so the checkin_mtime() SQL function
179	* does not lead to SQLITE_ABORT_ROLLBACK during execution of the OP_OpenRead
180	* SQLite opcode. checkin_mtime() calls mtime_of_manifest_file() which
181	* creates a temporary table if it doesn't already exist, thus invalidating
182	* the prepared statement in the middle of its execution. */
183	db_multi_exec("CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY)");







184
185	/* Append an ORDER BY clause then compile the query. */
186	blob_append_sql(&sql, " ORDER BY pathname");
187	db_prepare(&q, "%s", blob_sql_text(&sql));
188	blob_reset(&sql);
189

M src/descendants.c

+2 -2

		--- src/descendants.c
		+++ src/descendants.c
		@@ -216,12 +216,12 @@
216	216	static int prevVid = -1;
217	217	static Stmt q;
218	218
219	219	if( prevVid!=vid ){
220	220	prevVid = vid;
221		- db_multi_exec("DROP TABLE IF EXISTS temp.ok;"
222		- "CREATE TEMP TABLE ok(x INTEGER PRIMARY KEY);");
	221	+ db_multi_exec("CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY);"
	222	+ "DELETE FROM ok;");
223	223	compute_ancestors(vid, 100000000, 1);
224	224	}
225	225	db_static_prepare(&q,
226	226	"SELECT (max(event.mtime)-2440587.5)*86400 FROM mlink, event"
227	227	" WHERE mlink.mid=event.objid"
228	228

	--- src/descendants.c
	+++ src/descendants.c
	@@ -216,12 +216,12 @@
216	static int prevVid = -1;
217	static Stmt q;
218
219	if( prevVid!=vid ){
220	prevVid = vid;
221	db_multi_exec("DROP TABLE IF EXISTS temp.ok;"
222	"CREATE TEMP TABLE ok(x INTEGER PRIMARY KEY);");
223	compute_ancestors(vid, 100000000, 1);
224	}
225	db_static_prepare(&q,
226	"SELECT (max(event.mtime)-2440587.5)*86400 FROM mlink, event"
227	" WHERE mlink.mid=event.objid"
228

	--- src/descendants.c
	+++ src/descendants.c
	@@ -216,12 +216,12 @@
216	static int prevVid = -1;
217	static Stmt q;
218
219	if( prevVid!=vid ){
220	prevVid = vid;
221	db_multi_exec("CREATE TEMP TABLE IF NOT EXISTS ok(rid INTEGER PRIMARY KEY);"
222	"DELETE FROM ok;");
223	compute_ancestors(vid, 100000000, 1);
224	}
225	db_static_prepare(&q,
226	"SELECT (max(event.mtime)-2440587.5)*86400 FROM mlink, event"
227	" WHERE mlink.mid=event.objid"
228

Fossil SCM

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