fix/resolve bug fetching more history (#1176)

Co-authored-by: GitHub Action <action@github.com>

src/commitSha.ts

@@ -137,7 +137,7 @@ export const getSHAForPushEvent = async (
     }
 
     await verifyCommitSha({sha: previousSha, cwd: workingDirectory})
-    core.info(`Previous SHA: ${previousSha}`)
+    core.debug(`Previous SHA: ${previousSha}`)
 
     return {
       previousSha,
@@ -177,10 +177,6 @@ export const getSHAForPushEvent = async (
       core.debug('Getting previous SHA for last remote commit...')
       if (env.GITHUB_EVENT_FORCED === 'false' || !env.GITHUB_EVENT_FORCED) {
         previousSha = env.GITHUB_EVENT_BEFORE
-      } else {
-        previousSha = await getParentSha({
-          cwd: workingDirectory
-        })
       }
 
       if (
@@ -190,6 +186,19 @@ export const getSHAForPushEvent = async (
         previousSha = await getParentSha({
           cwd: workingDirectory
         })
+      } else if (
+        (await verifyCommitSha({
+          sha: previousSha,
+          cwd: workingDirectory,
+          showAsErrorMessage: false
+        })) !== 0
+      ) {
+        core.warning(
+          `Previous commit ${previousSha} is not valid. Using parent commit.`
+        )
+        previousSha = await getParentSha({
+          cwd: workingDirectory
+        })
       }
 
       if (previousSha === currentSha) {
@@ -322,7 +331,7 @@ export const getSHAForPullRequestEvent = async (
     }
 
     await verifyCommitSha({sha: currentSha, cwd: workingDirectory})
-    core.info(`Previous SHA: ${previousSha}`)
+    core.debug(`Previous SHA: ${previousSha}`)
 
     return {
       previousSha,