[PATCH] vcs_info patch2subject: Support `svn log -r N --diff` output.

[Daniel Shahaf <d.s@daniel.shahaf.name>]

---
This is used by the Debian libserf-1-1 package.

 Functions/VCS_Info/VCS_INFO_patch2subject | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Functions/VCS_Info/VCS_INFO_patch2subject b/Functions/VCS_Info/VCS_INFO_patch2subject
index e222e8382..a48c16b04 100644
--- a/Functions/VCS_Info/VCS_INFO_patch2subject
+++ b/Functions/VCS_Info/VCS_INFO_patch2subject
@@ -6,14 +6,18 @@
     integer -r LIMIT=10
     local -a lines
     local needle
+    readonly svn_log_pattern='^r[0-9]* [|] .*'
     if [[ -f "$1" ]]; then
         # Extract the first LIMIT lines, or up to the first empty line or the start of the unidiffs,
         # whichever comes first.
         while (( i++ < LIMIT )); do
             IFS= read -r "lines[$i]"
-            if [[ -z ${lines[$i]} ]] || [[ ${lines[$i]} == (#b)(---|Index:)* ]]; then
+            if [[ -z ${lines[$i]} ]] || [[ ${lines[$i]} == (#b)(---[^-]|Index:)* ]]; then
                 lines[$i]=()
-                break
+                # For 'svn log -r N --diff' output, read the first paragraph too.
+                if ! [[ $lines[i-1] =~ $svn_log_pattern ]]; then
+                    break
+                fi
             fi
         done < "$1"
         
@@ -51,6 +55,9 @@
               fi
             } < "$1"
             REPLY=$needle
+        elif [[ $lines[2] =~ $svn_log_pattern ]]; then
+            REPLY=$lines[4]
+            if (( ${+lines[5]} )); then REPLY+='...'; fi
         elif (( ${+lines[1]} )); then
             # The first line of the file is not part of the diff.
             REPLY=${lines[1]}