Fix bug #15841 with missing line numbers in linum-mode.

 src/search.c (find_newline): If buffer text is relocated during the
 "dumb loop", adjust C pointers into buffer text to follow suit.

2 files changed, 34 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 5ff279a4400..9a485533266 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-09  Eli Zaretskii  <eliz@gnu.org>
+
+        * search.c (find_newline): If buffer text is relocated during the
+        "dumb loop", adjust C pointers into buffer text to follow suit.
+        (Bug#15841)
+
 2013-11-09  Łukasz Stelmach <stlman@poczta.fm> (tiny change)
 
         * gtkutil.c (xg_check_special_colors): Use rgb: instead of rgbi:
diff --git a/src/search.c b/src/search.c
index 99e8d2501fe..1d0740428d7 100644
--- a/src/search.c
+++ b/src/search.c
@@ -752,6 +752,22 @@ find_newline (ptrdiff_t start, ptrdiff_t start_byte, ptrdiff_t end,
                     *bytepos = nl + 1 - base + start_byte;
                   return BYTE_TO_CHAR (nl + 1 - base + start_byte);
                 }
+              if (newline_cache)
+                {
+                  /* The call to know_region_cache could have
+                     allocated memory and caused relocation of buffer
+                     text.  If it did, adjust pointers into buffer
+                     text.  */
+                  ptrdiff_t offset = BYTE_POS_ADDR (start_byte) - base;
+
+                  if (offset != 0)
+                    {
+                      cursor += offset;
+                      base += offset;
+                      ceiling_addr += offset;
+                      nl += offset;
+                    }
+                }
               cursor = nl + 1;
             }
 
@@ -824,6 +840,18 @@ find_newline (ptrdiff_t start, ptrdiff_t start_byte, ptrdiff_t end,
                     *bytepos = nl - base + start_byte;
                   return BYTE_TO_CHAR (nl - base + start_byte);
                 }
+              if (newline_cache)
+                {
+                  ptrdiff_t offset = BYTE_POS_ADDR (start_byte - 1) - base;
+
+                  if (offset != 0)
+                    {
+                      cursor += offset;
+                      base += offset;
+                      ceiling_addr += offset;
+                      nl += offset;
+                    }
+                }
               cursor = nl - 1;
             }