ci: support no previous stable tags (#372)

.github/workflows/trigger-push-canary.yaml

@@ -43,8 +43,21 @@ jobs:
             chart_name=$(echo ${chart_dir} | cut -d '/' -f 2)
 
             latest_version="$(git -c 'versionsort.suffix=-' tag --sort 'version:refname' --list "$chart_name-*" | grep -Ev '.*-[[:digit:]]+.[[:digit:]]+.[[:digit:]]+-.*' | tail -n1)"
+            next_patch=""
+
+            if [ -z "$latest_version" ]; then
+              latest_version="$(git -c 'versionsort.suffix=-' tag --sort 'version:refname' --list "$chart_name-*" | tail -n1 | sed 's/-canary\.[0-9]*//')"
+              next_patch="$(echo ${latest_version} | sed 's/.*-\([0-9]\+\.[0-9]\+\.[0-9]\+\).*/\1/')"
+            fi
+
+            if [ -z "$latest_version" ]; then
+              latest_version="0.0.0"
+            fi
+
+            if [ -z "$next_patch" ]; then
+              next_patch="$(echo "$latest_version" | sed -E 's/(.*-)?([[:digit:]]+).([[:digit:]]+).([[:digit:]]+)/echo \2.\3.$((\4 + 1))/e')"
+            fi
 
-            next_patch="$(echo "$latest_version" | sed -E 's/(.*-)?([[:digit:]]+).([[:digit:]]+).([[:digit:]]+)/echo \2.\3.$((\4 + 1))/e')"
             last_pre_tag="$(git -c 'versionsort.suffix=-' tag --sort 'version:refname' --list "$chart_name-$next_patch-*" | tail -n1)"
             if [ -z "$last_pre_tag" ]; then
               index=1