Ensure single quotes are used for string literals.

SQLite 3.27.0 introduced a change in behaviour and started issuing
warnings to the error log when double quotes were being used for string
literals.  This happens to have been the way pkgin would insert every
package into the database, causing huge disk I/O to the sql.log file
when running "pkgin update".

At best this was significantly impacting runtime by orders of magnitude
and wasting disk space with large sql.log files, and at worst this was
reproducibly causing updates to fail entirely with "Short read of
pkg_summary: Lzma library error:  No progress is possible".

The exact details of why the extra logging was causing lzma failures is
still unclear and needs to be looked into to ensure we aren't missing
something else, but this change is demonstrated to avoid the issue.

pkgindb.c

@@ -375,7 +375,7 @@ pkg_sum_mtime(char *repo)
 	str_mtime[0] = '\0';
 
 	snprintf(query, BUFSIZ,
-		"SELECT REPO_MTIME FROM REPOS WHERE REPO_URL GLOB \'%s*\';",
+		"SELECT REPO_MTIME FROM REPOS WHERE REPO_URL GLOB '%s*';",
 		repo);
 	pkgindb_doquery(query, pdb_get_value, str_mtime);
 

pkgindb_queries.c

@@ -114,9 +114,9 @@ const char LOCAL_PROVIDES[] =
 	"SELECT LOCAL_PROVIDES_PKGNAME FROM LOCAL_PROVIDES;";
 
 const char KEEP_PKG[] =
-	"UPDATE LOCAL_PKG SET PKG_KEEP = 1 WHERE PKGNAME = \'%s\';";
+	"UPDATE LOCAL_PKG SET PKG_KEEP = 1 WHERE PKGNAME = '%s';";
 const char UNKEEP_PKG[] =
-	"UPDATE LOCAL_PKG SET PKG_KEEP = NULL WHERE PKGNAME = \'%s\';";
+	"UPDATE LOCAL_PKG SET PKG_KEEP = NULL WHERE PKGNAME = '%s';";
 
 const char INSERT_REMOTE_PKG[] =
 	"INSERT INTO REMOTE_PKG (PKG_ID,FULLPKGNAME,PKGNAME,PKGVERS,BUILD_DATE,"
@@ -162,7 +162,7 @@ const char KEEP_LOCAL_PKGS[] =
 	"FROM LOCAL_PKG WHERE PKG_KEEP IS NOT NULL;";
 
 const char PKG_URL[] =
-	"SELECT REPOSITORY FROM REMOTE_PKG WHERE FULLPKGNAME = \'%s\';";
+	"SELECT REPOSITORY FROM REMOTE_PKG WHERE FULLPKGNAME = '%s';";
 
 const char DELETE_EMPTY_ROWS[] =
 	"DELETE FROM REMOTE_PKG WHERE PKGNAME IS NULL;";
@@ -171,22 +171,22 @@ const char SELECT_REPO_URLS[] =
 	"SELECT REPO_URL FROM REPOS;";
 
 const char EXISTS_REPO[] =
-	"SELECT COUNT(*) FROM REPOS WHERE REPO_URL = \'%s\';";
+	"SELECT COUNT(*) FROM REPOS WHERE REPO_URL = '%s';";
 
 const char INSERT_REPO[] =
-	"INSERT INTO REPOS (REPO_URL, REPO_MTIME) VALUES (\'%s\', 0);";
+	"INSERT INTO REPOS (REPO_URL, REPO_MTIME) VALUES ('%s', 0);";
 
 const char UPDATE_REPO_MTIME[] =
-	"UPDATE REPOS SET REPO_MTIME = %lld WHERE REPO_URL = \'%s\';";
+	"UPDATE REPOS SET REPO_MTIME = %lld WHERE REPO_URL = '%s';";
 
 const char DELETE_REPO_URL[] =
-	"DELETE FROM REPOS WHERE REPO_URL = \'%s\';";
+	"DELETE FROM REPOS WHERE REPO_URL = '%s';";
 
 const char INSERT_SINGLE_VALUE[] =
-	"INSERT INTO %s (PKG_ID, %s_PKGNAME) VALUES (%d,\"%s\");";
+	"INSERT INTO %s (PKG_ID, %s_PKGNAME) VALUES (%d,'%s');";
 
 const char INSERT_DEPENDS_VALUES[] = 
-	"INSERT INTO %s (PKG_ID, %s_PKGNAME, %s_DEWEY) VALUES (%d,\"%s\",\"%s\");";
+	"INSERT INTO %s (PKG_ID, %s_PKGNAME, %s_DEWEY) VALUES (%d,'%s','%s');";
 
 const char UNIQUE_PKG[] = 
 	"SELECT FULLPKGNAME, PKGVERS FROM %s WHERE PKGNAME = '%s';";

summary.c

@@ -210,7 +210,7 @@ prepare_insert(int pkgid, struct Summary sum)
 
 	/* insert fields */
 	SLIST_FOREACH(pi, &inserthead, next) {
-		snprintf(tmpbuf, sizeof(tmpbuf), ",\"%s\"", pi->field);
+		snprintf(tmpbuf, sizeof(tmpbuf), ",%s", pi->field);
 		if (strlcat(querybuf, tmpbuf, sizeof(querybuf)) >= sizeof(querybuf))
 			goto err;
 	}
@@ -221,7 +221,7 @@ prepare_insert(int pkgid, struct Summary sum)
 
 	/* insert values */
 	SLIST_FOREACH(pi, &inserthead, next) {
-		snprintf(tmpbuf, sizeof(tmpbuf), ",\"%s\"", pi->value);
+		snprintf(tmpbuf, sizeof(tmpbuf), ",'%s'", pi->value);
 		if (strlcat(querybuf, tmpbuf, sizeof(querybuf)) >= sizeof(querybuf))
 			goto err;
 	}
@@ -261,7 +261,7 @@ parse_entry(struct Summary sum, int pkgid, char *line)
 {
 	static uint8_t	check_machine_arch = 1;
 	int		i;
-	char		*val, *v, *pkg, buf[BUFSIZ];
+	char		*val, *v, *p, *pkg, buf[BUFSIZ], *tmp;
 
 	if ((val = strchr(line, '=')) == NULL)
 		errx(EXIT_FAILURE, "Invalid pkg_info entry: %s", line);
@@ -336,14 +336,25 @@ parse_entry(struct Summary sum, int pkgid, char *line)
 		snprintf(buf, BUFSIZ, "%s=", cols.name[i]);
 
 		if (strncmp(buf, line, strlen(buf)) == 0) {
+			tmp = NULL;
 			/*
-			 * Avoid double quotes in our query by using
-			 * the MySQL-compatible "`" instead.
+			 * Convert single quotes to SQLite compatible ''.
 			 */
-			if (strchr(val, '"') != NULL)
-				for (v = val; *v != '\0'; v++)
-					if (*v == '"')
-						*v = '`';
+			if (strchr(val, '\'') != NULL) {
+				for (v = p = val; *v != '\0'; v++) {
+					if (*v != '\'')
+						continue;
+
+					*v = '\0';
+					if (tmp)
+						tmp = xasprintf("%s%s''", tmp, p);
+					else
+						tmp = xasprintf("%s''", p);
+					p = v + 1;
+				}
+				tmp = xasprintf("%s%s", tmp, p);
+				val = tmp;
+			}
 
 			/* Split PKGNAME into parts */
 			if (strncmp(cols.name[i], "PKGNAME", 7) == 0) {
@@ -364,6 +375,7 @@ parse_entry(struct Summary sum, int pkgid, char *line)
 			} else
 				add_to_slist(cols.name[i], val);
 
+			free(tmp);
 			break;
 		}
 	}