Also include errors assoicated with line 0 (e.g. copyright errors).

To do this we need to not error exit if the grep fails to find any valid
lines. We still care about these files (this can happen if, for example,
only lines are removed from the file).

Author: thk123

scripts/run_lint.sh

@@ -37,19 +37,16 @@ IFS=$'\n'
 are_errors=0
 
 for file in $diff_files; do
-  # We first filter only the lines that start with a commit hash
-  # Then we filter out the ones that come from the start commit
-  modified_lines=`git blame $git_start..$git_end --line-porcelain $file | grep -E "^[0-9a-f]{40}" | grep -v "$blame_grep_filter"`
+  # We build another grep filter the output of the linting script
+  lint_grep_filter="^("
 
-  if [ -z "$modified_lines" ]
-  then
-    # No modified lines in this file (perhaps only lines have been deleted)
-    # So we bail on reporting errors on this file
-    continue
-  fi
+  # Include line 0 errors (e.g. copyright)
+  lint_grep_filter+=$file
+  lint_grep_filter+=":0"
 
-  # Next we build another grep filter the output of the linting script
-  lint_grep_filter="^("
+  # We first filter only the lines that start with a commit hash
+  # Then we filter out the ones that come from the start commit
+  modified_lines=`git blame $git_start..$git_end --line-porcelain $file | grep -E "^[0-9a-f]{40}" | { grep -v "$blame_grep_filter" || true; }`
 
   # For each modified line we find the line number
   for line in $modified_lines; do
@@ -66,13 +63,12 @@ for file in $diff_files; do
 
       # Add the line filter on to the grep expression as we want
       # lines that match any of the line filters
-      lint_grep_filter+=$LINE_FILTER
       lint_grep_filter+="|"
+      lint_grep_filter+=$LINE_FILTER
     fi
   done
 
-  # Knock off the final pipe and add the closing bracket
-  lint_grep_filter=${lint_grep_filter::-1}
+  # Add the closing bracket
   lint_grep_filter+=")"
 
   # Run the linting script and filter by the filter we've build