https://bugs.gentoo.org/360849

support opening the compressed pci/usb databases

--- a/extras/usb-db/usb-db.c
+++ b/extras/usb-db/usb-db.c
@@ -90,19 +90,60 @@
 #define HEXCHARS "0123456789abcdefABCDEF"
 #define WHITESPACE " \t\n\r"
 
+#ifdef USE_ZLIB
+
+#include <zlib.h>
+
+static ssize_t gz_getline(char **lineptr, size_t *n, void *stream)
+{
+	if (!*lineptr)
+		*lineptr = malloc(*n = 4096);
+	if (!*lineptr)
+		return -1;
+	if (gzgets(stream, *lineptr, *n - 1)) {
+		(*lineptr)[*n - 1] = '\0';
+		/* should return strlen(*lineptr), but caller doesn't care */
+		return 0;
+	}
+	return -1;
+}
+static int gz_fclose(void *stream)
+{
+	return gzclose(stream);
+}
+
+static ssize_t stdio_getline(char **lineptr, size_t *n, void *stream)
+{
+	return getline(lineptr, n, stream);
+}
+static int stdio_fclose(void *stream)
+{
+	return fclose(stream);
+}
+
+#endif
+
 static int lookup_vid_pid(
 	uint16_t vid,
 	uint16_t pid,
 	char **vendor,
 	char **product) {
 
-	FILE *f;
+	void *f;
 	int ret = -1;
 	int found_vendor = 0;
 	char *line = NULL;
 
 	*vendor = *product = NULL;
 
+#ifdef USE_ZLIB
+	ssize_t (*getline)(char **lineptr, size_t *n, void *stream) = stdio_getline;
+	int (*fclose)(void *stream) = stdio_fclose;
+	if ((f = gzopen(DATABASE ".gz", "r"))) {
+		getline = gz_getline;
+		fclose = gz_fclose;
+	} else
+#endif
 	if (!(f = fopen(DATABASE, "r"))) {
 		fprintf(stderr, "Failed to open database file "DATABASE": %s\n", strerror(errno));
 		return -1;
@@ -111,11 +152,6 @@
 	for (;;) {
 		size_t n;
 
-		if (line) {
-			free(line);
-			line = NULL;
-		}
-
 		if (getline(&line, &n, f) < 0)
 			break;
 
--- a/Makefile.in
+++ b/Makefile.in
@@ -987,7 +987,7 @@
 # ------------------------------------------------------------------------------
 @ENABLE_HWDB_TRUE@extras_usb_db_usb_db_SOURCES = extras/usb-db/usb-db.c
-@ENABLE_HWDB_TRUE@extras_usb_db_usb_db_CPPFLAGS = $(AM_CPPFLAGS) -DUSB_DATABASE=\"$(USB_DATABASE)\" -DBUILD_FOR_USB
+@ENABLE_HWDB_TRUE@extras_usb_db_usb_db_CPPFLAGS = $(AM_CPPFLAGS) -DUSB_DATABASE=\"$(USB_DATABASE)\" -DBUILD_FOR_USB -DUSE_ZLIB
-@ENABLE_HWDB_TRUE@extras_usb_db_usb_db_LDADD = libudev/libudev-private.la
+@ENABLE_HWDB_TRUE@extras_usb_db_usb_db_LDADD = libudev/libudev-private.la -lz
 @ENABLE_HWDB_TRUE@extras_usb_db_pci_db_SOURCES = extras/usb-db/usb-db.c
-@ENABLE_HWDB_TRUE@extras_usb_db_pci_db_CPPFLAGS = $(AM_CPPFLAGS) -DPCI_DATABASE=\"$(PCI_DATABASE)\" -DBUILD_FOR_PCI
+@ENABLE_HWDB_TRUE@extras_usb_db_pci_db_CPPFLAGS = $(AM_CPPFLAGS) -DPCI_DATABASE=\"$(PCI_DATABASE)\" -DBUILD_FOR_PCI -DUSE_ZLIB
-@ENABLE_HWDB_TRUE@extras_usb_db_pci_db_LDADD = libudev/libudev-private.la
+@ENABLE_HWDB_TRUE@extras_usb_db_pci_db_LDADD = libudev/libudev-private.la -lz