From 4c30d368bca8b3f108a7e86a5b890e33470cdebf Mon Sep 17 00:00:00 2001
From: Ken Hornstein <kenh@pobox.com>
Date: Thu, 14 Nov 2013 11:43:33 -0500
Subject: [PATCH] Break out the unquote functionality to a separate function.

---
 h/prototypes.h  |   17 +++++++++++++++++
 sbr/Makefile.in |    3 ++-
 sbr/fmt_scan.c  |   24 +-----------------------
 sbr/unquote.c   |   45 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 65 insertions(+), 24 deletions(-)
 create mode 100644 sbr/unquote.c

diff --git a/h/prototypes.h b/h/prototypes.h
index 848115f..42767f5 100644
--- a/h/prototypes.h
+++ b/h/prototypes.h
@@ -112,6 +112,23 @@ int uprf(char *, char *);
 int vfgets(FILE *, char **);
 char *write_charset_8bit(void);
 
+/*
+ * Remove quotes and quoted-pair sequences from RFC-5322 atoms.
+ *
+ * Currently the actual algorithm is simpler than it technically should
+ * be: any quotes are simply eaten, unless they're preceded by the escape
+ * character (\).  This seems to be sufficient for our needs for now.
+ *
+ * Arguments:
+ *
+ * input	- The input string
+ * output	- The output string; is assumed to have at least as much
+ *		  room as the input string.  At worst the output string will
+ *		  be the same size as the input string; it might be smaller.
+ *
+ */
+void unquote_string(const char *input, char *output);
+
 int mh_strcasecmp(const char *s1, const char *s2);
 
 
diff --git a/sbr/Makefile.in b/sbr/Makefile.in
index 61fc96c..4d2b91b 100644
--- a/sbr/Makefile.in
+++ b/sbr/Makefile.in
@@ -69,7 +69,8 @@ SRCS = addrsbr.c ambigsw.c brkstring.c  \
 	seq_setprev.c seq_setunseen.c signals.c  \
 	smatch.c snprintb.c strcasecmp.c  \
 	strindex.c trim.c trimcpy.c uprf.c vfgets.c fmt_def.c  \
-	mf.c utils.c m_mktemp.c seq_msgstats.c
+	mf.c utils.c m_mktemp.c seq_msgstats.c \
+	unquote.c
 
 OBJS =  $(SRCS:.c=.o)
 
diff --git a/sbr/fmt_scan.c b/sbr/fmt_scan.c
index a8e773a..6cfc176 100644
--- a/sbr/fmt_scan.c
+++ b/sbr/fmt_scan.c
@@ -688,32 +688,10 @@ fmt_scan(struct format *format, char *scanl, int width, int *dat)
 		/* UNQUOTEs RFC-2822 quoted-string and quoted-pair */
 		case FT_LS_UNQUOTE:
 			if (str) {
-				int m;
 				strncpy(buffer, str, sizeof(buffer));
 				/* strncpy doesn't NUL-terminate if it fills the buffer */
 				buffer[sizeof(buffer)-1] = '\0';
-				str = buffer;
-
-				/* we will parse from buffer to buffer2 */
-				n = 0; /* n is the input position in str */
-				m = 0; /* m is the ouput position in buffer2 */
-
-				while ( str[n] != '\0') {
-					switch ( str[n] ) {
-					case '\\':
-						n++;
-						if ( str[n] != '\0')
-							buffer2[m++] = str[n++];
-						break;
-					case '"':
-						n++;
-						break;
-					default:
-						buffer2[m++] = str[n++];
-						break;
-					}
-				}
-				buffer2[m] = '\0';
+				unquote_string(buffer, buffer2);
 				str = buffer2;
 			}
 			break;
diff --git a/sbr/unquote.c b/sbr/unquote.c
new file mode 100644
index 0000000..f9fa911
--- /dev/null
+++ b/sbr/unquote.c
@@ -0,0 +1,45 @@
+/*
+ * unquote.c: Handle quote removal and quoted-pair strings on
+ * RFC 2822-5322 atoms.
+ *
+ * This code is Copyright (c) 2013, by the authors of nmh.  See the
+ * COPYRIGHT file in the root directory of the nmh distribution for
+ * complete copyright information.
+ */
+
+#include <h/mh.h>
+
+/*
+ * Remove quotes (and handle escape strings) from RFC 5322 quoted-strings.
+ *
+ * Since we never add characters to the string, the output buffer is assumed
+ * to have at least as many characters as the input string.
+ *
+ */
+
+void
+unquote_string(const char *input, char *output)
+{
+    int n = 0;	/* n is the position in the input buffer */
+    int m = 0;	/* m is the position in the output buffer */
+
+    while ( input[n] != '\0') {
+	switch ( input[n] ) {
+	case '\\':
+	    n++;
+	    if ( input[n] != '\0')
+		output[m++] = input[n++];
+	    break;
+	case '"':
+	    n++;
+	    break;
+	default:
+	    output[m++] = input[n++];
+	    break;
+	}
+    }
+
+    output[m] = '\0';
+
+    return;
+}
-- 
1.7.10.4