pkg/email: support quilt patch format

Quilt uses a slightly different patch format to traditional git
diff/format-patch. Support it.

pkg/email/parser_test.go

@@ -428,7 +428,9 @@ IHQpKSB7CiAJCXNwaW5fdW5sb2NrKCZrY292LT5sb2NrKTsKIAkJcmV0dXJuOwo=
 			Body: `body text
 >#syz test
 `,
-			Patch: `--- a/kernel/kcov.c
+			Patch: `diff --git a/kernel/kcov.c b/kernel/kcov.c
+index 85e5546cd791..949ea4574412 100644
+--- a/kernel/kcov.c
 +++ b/kernel/kcov.c
 @@ -127,7 +127,6 @@ void kcov_task_exit(struct task_struct *t)
  	kcov = t->kcov;
@@ -537,7 +539,9 @@ index 3d85747bd86e..a257b872a53d 100644
   error = vfs_statx(dfd, filename, flags, &stat, mask);
   if (error)
 `,
-			Patch: `--- a/fs/stat.c
+			Patch: `diff --git a/fs/stat.c b/fs/stat.c
+index 3d85747bd86e..a257b872a53d 100644
+--- a/fs/stat.c
 +++ b/fs/stat.c
 @@ -567,8 +567,6 @@ SYSCALL_DEFINE5(statx,
   return -EINVAL;

pkg/email/patch.go

@@ -6,33 +6,35 @@ package email
 import (
 	"bufio"
 	"fmt"
+	"regexp"
 	"strings"
 )
 
 func ParsePatch(text string) (title string, diff string, err error) {
 	s := bufio.NewScanner(strings.NewReader(text))
-	parsingDiff := false
-	diffStarted := false
 	lastLine := ""
+	diffStarted := false
 	for s.Scan() {
 		ln := s.Text()
-		if strings.HasPrefix(ln, "--- a/") || strings.HasPrefix(ln, "--- /dev/null") {
-			parsingDiff = true
+		if lineMatchesDiffStart(ln) {
+			diffStarted = true
+			diff += ln + "\n"
 			if title == "" {
 				title = lastLine
 			}
+			continue
 		}
-		if parsingDiff {
-			if ln == "" || ln == "--" || ln == "-- " || ln[0] == '>' ||
-				ln[0] >= 'A' && ln[0] <= 'Z' {
-				break
+		if diffStarted {
+			if ln == "" || ln == "--" || ln == "-- " || ln[0] == '>' {
+				diffStarted = false
+				continue
+			}
+			if strings.HasPrefix(ln, " ") || strings.HasPrefix(ln, "+") ||
+				strings.HasPrefix(ln, "-") || strings.HasPrefix(ln, "@") ||
+				strings.HasPrefix(ln, "================") {
+				diff += ln + "\n"
+				continue
 			}
-			diff += ln + "\n"
-			continue
-		}
-		if strings.HasPrefix(ln, "diff --git") {
-			diffStarted = true
-			continue
 		}
 		if strings.HasPrefix(ln, "Subject: ") {
 			title = ln[len("Subject: "):]
@@ -68,3 +70,19 @@ func ParsePatch(text string) (title string, diff string, err error) {
 	}
 	return
 }
+
+func lineMatchesDiffStart(ln string) bool {
+	diffRegexps := []*regexp.Regexp{
+		regexp.MustCompile(`^(---|\+\+\+) [^\s]`),
+		regexp.MustCompile(`^diff --git`),
+		regexp.MustCompile(`^index [0-9a-f]+\.\.[0-9a-f]+`),
+		regexp.MustCompile(`^new file mode [0-9]+`),
+		regexp.MustCompile(`^Index: [^\s]`),
+	}
+	for _, re := range diffRegexps {
+		if re.MatchString(ln) {
+			return true
+		}
+	}
+	return false
+}

pkg/email/patch_test.go

@@ -64,7 +64,9 @@ index 74e0388cc88d..fc6f740d0277 100644
  	}
 `,
 		title: "net/tcp: fix foo()",
-		diff: `--- a/kernel/time/tick-sched.c
+		diff: `diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
+index 74e0388cc88d..fc6f740d0277 100644
+--- a/kernel/time/tick-sched.c
 +++ b/kernel/time/tick-sched.c
 @@ -725,6 +725,11 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
  		 */
@@ -101,7 +103,9 @@ index acbe61c..160dc89 100644
  	irda_queue_t* queue;
 `,
 		title: "fix looking up invalid subclass: 4294967295",
-		diff: `--- a/net/irda/irqueue.c
+		diff: `diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c
+index acbe61c..160dc89 100644
+--- a/net/irda/irqueue.c
 +++ b/net/irda/irqueue.c
 @@ -383,9 +383,6 @@ EXPORT_SYMBOL(hashbin_new);
   *    for deallocating this structure if it's complex. If not the user can
@@ -131,7 +135,9 @@ index acbe61c..160dc89 100644
 -#endif
  int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)`,
 		title: "net: fix looking up invalid subclass: 4294967295",
-		diff: `--- a/net/irda/irqueue.c
+		diff: `diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c
+index acbe61c..160dc89 100644
+--- a/net/irda/irqueue.c
 +++ b/net/irda/irqueue.c
 @@ -383,9 +383,6 @@ EXPORT_SYMBOL(hashbin_new);
   *    for deallocating this structure if it's complex. If not the user can
@@ -212,7 +218,10 @@ index 36870b2..5484d77 100644
 -- 
 2.5.5`,
 		title: "crypto/sha512-mb: Correct initialization value for lane lens",
-		diff: `--- a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_init_avx2.c
+		diff: `diff --git a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_init_avx2.c ` +
+			`b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_init_avx2.c
+index 36870b2..5484d77 100644
+--- a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_init_avx2.c
 +++ b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_init_avx2.c
 @@ -57,10 +57,10 @@ void sha512_mb_mgr_init_avx2(struct sha512_mb_mgr *state)
  {
@@ -300,7 +309,10 @@ index 0000000..a1a0499
 +package dash
 `,
 		title: "syz-dash: first version of dashboard app",
-		diff: `--- /dev/null
+		diff: `diff --git a/syz-dash/api.go b/syz-dash/api.go
+new file mode 100644
+index 0000000..a1a0499
+--- /dev/null
 +++ b/syz-dash/api.go
 @@ -0,0 +1,444 @@
 +package dash
@@ -339,7 +351,9 @@ index 6f319fb81718..76a8d5aeed4b 100644
 > Does this help?
 `,
 		title: "multi-file patch",
-		diff: `--- a/init/main.c
+		diff: `diff --git a/init/main.c b/init/main.c
+index 0ee9c6866ada..ed01296f7b23 100644
+--- a/init/main.c
 +++ b/init/main.c
 @@ -706,6 +706,8 @@ asmlinkage __visible void __init start_kernel(void)
                 efi_free_boot_services();
@@ -363,6 +377,107 @@ index 6f319fb81718..76a8d5aeed4b 100644
  }
  
  void kasan_disable_current(void)
+`,
+	},
+	{
+		text: `Subject: Re: WARNING in usb_submit_urb (4)
+
+#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git v5.1-rc3
+
+Index: usb-devel/drivers/usb/core/driver.c
+===================================================================
+--- usb-devel.orig/drivers/usb/core/driver.c
++++ usb-devel/drivers/usb/core/driver.c
+@@ -34,6 +34,9 @@
+ 
+ #include "usb.h"
+ 
++#undef dev_vdbg
++#define dev_vdbg dev_info
++
+ 
+ /*
+  * Adds a new dynamic USBdevice ID to this driver,
+Index: usb-devel/drivers/usb/core/hub.c
+===================================================================
+--- usb-devel.orig/drivers/usb/core/hub.c
++++ usb-devel/drivers/usb/core/hub.c
+@@ -36,6 +36,10 @@
+ #include "hub.h"
+ #include "otg_whitelist.h"
+ 
++#undef dev_dbg
++#define dev_dbg dev_info
++
++
+ #define USB_VENDOR_GENESYS_LOGIC		0x05e3
+ #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01
+ 
+@@ -1016,6 +1020,8 @@ static void hub_activate(struct usb_hub
+ 	bool need_debounce_delay = false;
+ 	unsigned delay;
+ 
++	dev_info(hub->intfdev, "%s type %d\n", __func__, type);
++
+ 	/* Continue a partial initialization */
+ 	if (type == HUB_INIT2 || type == HUB_INIT3) {
+ 		device_lock(&hdev->dev);
+@@ -1254,6 +1260,7 @@ static void hub_activate(struct usb_hub
+  init3:
+ 	hub->quiescing = 0;
+ 
++	dev_info(hub->intfdev, "Submitting status URB\n");
+ 	status = usb_submit_urb(hub->urb, GFP_NOIO);
+ 	if (status < 0)
+ 		dev_err(hub->intfdev, "activate --> %d\n", status);
+`,
+		title: "Re: WARNING in usb_submit_urb (4)",
+		diff: `Index: usb-devel/drivers/usb/core/driver.c
+===================================================================
+--- usb-devel.orig/drivers/usb/core/driver.c
++++ usb-devel/drivers/usb/core/driver.c
+@@ -34,6 +34,9 @@
+ 
+ #include "usb.h"
+ 
++#undef dev_vdbg
++#define dev_vdbg dev_info
++
+ 
+ /*
+  * Adds a new dynamic USBdevice ID to this driver,
+Index: usb-devel/drivers/usb/core/hub.c
+===================================================================
+--- usb-devel.orig/drivers/usb/core/hub.c
++++ usb-devel/drivers/usb/core/hub.c
+@@ -36,6 +36,10 @@
+ #include "hub.h"
+ #include "otg_whitelist.h"
+ 
++#undef dev_dbg
++#define dev_dbg dev_info
++
++
+ #define USB_VENDOR_GENESYS_LOGIC		0x05e3
+ #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01
+ 
+@@ -1016,6 +1020,8 @@ static void hub_activate(struct usb_hub
+ 	bool need_debounce_delay = false;
+ 	unsigned delay;
+ 
++	dev_info(hub->intfdev, "%s type %d\n", __func__, type);
++
+ 	/* Continue a partial initialization */
+ 	if (type == HUB_INIT2 || type == HUB_INIT3) {
+ 		device_lock(&hdev->dev);
+@@ -1254,6 +1260,7 @@ static void hub_activate(struct usb_hub
+  init3:
+ 	hub->quiescing = 0;
+ 
++	dev_info(hub->intfdev, "Submitting status URB\n");
+ 	status = usb_submit_urb(hub->urb, GFP_NOIO);
+ 	if (status < 0)
+ 		dev_err(hub->intfdev, "activate --> %d\n", status);
 `,
 	},
 }