From 0e7690deacc3232f1a0bd3902255ffa34292e5cf Mon Sep 17 00:00:00 2001
From: Claudio Bley <claudio.bley@googlemail.com>
Date: Fri, 1 Nov 2013 11:10:13 +0200
Subject: [PATCH] Fix handling of comments in NetPBM image files.

 src/image.c (pbm_next_char): New function.
 (pbm_scan_number): Use it.

 lisp/image.el (image-type-header-regexps): Fix the 'pbm' part to
 allow comments in pbm files.
---
 lisp/ChangeLog |  3 +++
 lisp/image.el  |  5 ++++-
 src/ChangeLog  |  4 +++-
 src/image.c    | 51 +++++++++++++++++++++++++++++---------------------
 4 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a73c38bd52..fd8e77c9c5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,8 @@
 2013-11-01  Claudio Bley  <claudio.bley@googlemail.com>
 
+	* image.el (image-type-header-regexps): Fix the 'pbm' part to
+	allow comments in pbm files.
+
 	* term/w32-win.el (dynamic-library-alist): Support newer versions
 	of libjpeg starting with v7: look only for the DLL from the
 	version against which Emacs was built.
diff --git a/lisp/image.el b/lisp/image.el
index 6ce5b82ec4..69d890719d 100644
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -34,7 +34,10 @@
 
 (defconst image-type-header-regexps
   `(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm)
-    ("\\`P[1-6][[:space:]]+\\(?:#.*[[:space:]]+\\)*[0-9]+[[:space:]]+[0-9]+" . pbm)
+    ("\\`P[1-6]\\\(?:\
+\\(?:\\(?:#[^\r\n]*[\r\n]\\)?[[:space:]]\\)+\
+\\(?:\\(?:#[^\r\n]*[\r\n]\\)?[0-9]\\)+\
+\\)\\{2\\}" . pbm)
     ("\\`GIF8[79]a" . gif)
     ("\\`\x89PNG\r\n\x1a\n" . png)
     ("\\`[\t\n\r ]*#define \\([a-z0-9_]+\\)_width [0-9]+\n\
diff --git a/src/ChangeLog b/src/ChangeLog
index 0d58733f4b..bfa2810557 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,6 +1,8 @@
 2013-11-01  Claudio Bley  <claudio.bley@googlemail.com>
 
-	* image.c (Qlibjpeg_version): New variable.
+	* image.c (pbm_next_char): New function.
+	(pbm_scan_number): Use it.
+	(Qlibjpeg_version): New variable.
 	(syms_of_image): DEFSYM and initialize it.
 
 2013-10-31  Jan Djärv  <jan.h.d@swipnet.se>
diff --git a/src/image.c b/src/image.c
index fca1bb077f..958295c5d0 100644
--- a/src/image.c
+++ b/src/image.c
@@ -5106,6 +5106,27 @@ pbm_image_p (Lisp_Object object)
 }
 
 
+/* Get next char skipping comments in Netpbm header.  Returns -1 at
+   end of input.  */
+
+static int
+pbm_next_char (unsigned char **s, unsigned char *end)
+{
+  int c = -1;
+
+  while (*s < end && (c = *(*s)++, c == '#'))
+    {
+      /* Skip to the next line break.  */
+      while (*s < end && (c = *(*s)++, c != '\n' && c != '\r'))
+        ;
+
+      c = -1;
+    }
+
+  return c;
+}
+
+
 /* Scan a decimal number from *S and return it.  Advance *S while
    reading the number.  END is the end of the string.  Value is -1 at
    end of input.  */
@@ -5115,28 +5136,16 @@ pbm_scan_number (unsigned char **s, unsigned char *end)
 {
   int c = 0, val = -1;
 
-  while (*s < end)
-    {
-      /* Skip white-space.  */
-      while (*s < end && (c = *(*s)++, c_isspace (c)))
-	;
+  /* Skip white-space.  */
+  while ((c = pbm_next_char (s, end)) != -1 && c_isspace (c))
+    ;
 
-      if (c == '#')
-	{
-	  /* Skip comment to end of line.  */
-	  while (*s < end && (c = *(*s)++, c != '\n'))
-	    ;
-	}
-      else if (c_isdigit (c))
-	{
-	  /* Read decimal number.  */
-	  val = c - '0';
-	  while (*s < end && (c = *(*s)++, c_isdigit (c)))
-	    val = 10 * val + c - '0';
-	  break;
-	}
-      else
-	break;
+  if (c_isdigit (c))
+    {
+      /* Read decimal number.  */
+      val = c - '0';
+      while ((c = pbm_next_char (s, end)) != -1 && c_isdigit (c))
+        val = 10 * val + c - '0';
     }
 
   return val;
-- 
2.20.1