Improve error handling in dbopen(). If PRAGMA SQL statements fail,

report the error, close the database, and return failure from dbopen(),
such that the main program can recover and rebuild the database.

As noticed by stsp@, this can happen when database files are
accessible, but corrupt or in the wrong format, which will now
automatically be repaired.

Besides, use a safer idiom after sqlite3_open*() failure that also
handles out-of-memory situations correctly, and do not forget to
close the database after CREATE TABLE failure.

1 files changed, 21 insertions, 6 deletions

diff --git a/mandocdb.c b/mandocdb.c
index 277c00dc..50a9bd91 100644
--- a/mandocdb.c
+++ b/mandocdb.c
@@ -2209,7 +2209,7 @@ dbopen(int real)
 		rc = sqlite3_open_v2(MANDOC_DB, &db, ofl, NULL);
 		if (SQLITE_OK != rc) {
 			exitcode = (int)MANDOCLEVEL_SYSERR;
-			say(MANDOC_DB, "%s", sqlite3_errmsg(db));
+			say(MANDOC_DB, "%s", sqlite3_errstr(rc));
 			return(0);
 		}
 		goto prepare_statements;
@@ -2223,7 +2223,7 @@ dbopen(int real)
 		goto create_tables;
 	if (MPARSE_QUICK & mparse_options) {
 		exitcode = (int)MANDOCLEVEL_SYSERR;
-		say(MANDOC_DB "~", "%s", sqlite3_errmsg(db));
+		say(MANDOC_DB "~", "%s", sqlite3_errstr(rc));
 		return(0);
 	}
 
@@ -2239,7 +2239,7 @@ dbopen(int real)
 	rc = sqlite3_open_v2(tempfilename, &db, ofl, NULL);
 	if (SQLITE_OK != rc) {
 		exitcode = (int)MANDOCLEVEL_SYSERR;
-		say("", "%s: %s", tempfilename, sqlite3_errmsg(db));
+		say("", "%s: %s", tempfilename, sqlite3_errstr(rc));
 		return(0);
 	}
 
@@ -2277,11 +2277,20 @@ create_tables:
 	if (SQLITE_OK != sqlite3_exec(db, sql, NULL, NULL, NULL)) {
 		exitcode = (int)MANDOCLEVEL_SYSERR;
 		say(MANDOC_DB, "%s", sqlite3_errmsg(db));
+		sqlite3_close(db);
 		return(0);
 	}
 
 prepare_statements:
-	SQL_EXEC("PRAGMA foreign_keys = ON");
+	if (SQLITE_OK != sqlite3_exec(db,
+	    "PRAGMA foreign_keys = ON", NULL, NULL, NULL)) {
+		exitcode = (int)MANDOCLEVEL_SYSERR;
+		say(MANDOC_DB, "PRAGMA foreign_keys: %s",
+		    sqlite3_errmsg(db));
+		sqlite3_close(db);
+		return(0);
+	}
+
 	sql = "DELETE FROM mpages WHERE pageid IN "
 		"(SELECT pageid FROM mlinks WHERE "
 		"sec=? AND arch=? AND name=?)";
@@ -2305,8 +2314,14 @@ prepare_statements:
 	 * synchronous mode for much better performance.
 	 */
 
-	if (real)
-		SQL_EXEC("PRAGMA synchronous = OFF");
+	if (real && SQLITE_OK != sqlite3_exec(db,
+	    "PRAGMA synchronous = OFF", NULL, NULL, NULL)) {
+		exitcode = (int)MANDOCLEVEL_SYSERR;
+		say(MANDOC_DB, "PRAGMA synchronous: %s",
+		sqlite3_errmsg(db));
+		sqlite3_close(db);
+		return(0);
+	}
 #endif
 
 	return(1);